Monthly Threat Report August 2023: WormGPT and an Increase in Email Security Threats

Monthly Threat Report August 2023: WormGPT and an Increase in Email Security Threats

Introduction

The Monthly Threat Report by Hornetsecurity brings you monthly insights into M365 security trends, email-based threats, and commentary on current events in the cybersecurity space. This edition of the Monthly Threat Report focuses on data for the month of July.

Executive Summary

  • Our tracked threat categories saw a net increase across the board for the month of July vs. June.
  • HTML files were the top file type for email attacks last month. This is largely because there was a significant decrease in malicious PDF usage by Qakbot.
  • The entertainment and research verticals were the most targeted businesses in the past month.
  • DHL continues to be the most impersonated brand, with impersonation attempts increasing for Sparkasse, LinkedIn, Mastercard, and Netflix.
  • New dark-web generative AI tools like WormGPT will likely increase Business Email Compromise attacks over the coming weeks and months.
  • There continue to be privacy failures, double-extortion attacks, and other fallout associated with the MOVEit file transfer software vulnerabilities from earlier this summer. If you haven’t patched yet, do so. TODAY.
  • A recent breach of Microsoft Cloud services by a Chinese threat actor is leading some experts in the industry to call Microsoft’s response to the breach into question. It is also likely to renew the conversation about cloud providers’ role in Security.
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Threat Overview

Unwanted Emails By Category

The following table shows the distribution of unwanted emails per category for July 2023 compared to June 2023.

 

Unwanted Emails by Category

This month saw a slight increase in the number of threatening emails. The amount of mail classified as “Spam” is up 2.9%, while the amount of mail classified as “Threat” and “AdvThreat” increased by 0.9% and 0.2%, respectively. This led to the amount of “Rejected” mail seeing a 3.9% reduction.

NOTE: As a reminder, the “Rejected” category refers to mail that Hornetsecurity services rejected during the SMTP dialog because of external characteristics, such as the sender’s identity or IP address. If a sender is already identified as compromised, the system does not proceed with further analysis. The SMTP server denies the email transfer right at the initial point of connection based on the negative reputation of the IP and the sender’s identity.

Other categories in the image are described in the table below:

Category Description
Spam These emails are unwanted and are often promotional or fraudulent. The emails are sent simultaneously to a large number of recipients.
Threat These emails contain harmful content, such as malicious attachments or links, or they are sent to commit crimes like phishing.
AdvThreat Advanced Threat Protection has detected a threat in these emails. The emails are used for illegal purposes and involve sophisticated technical means that can only be fended off using advanced dynamic procedures.
Rejected Our email server rejects these emails directly during the SMTP dialog because of external characteristics, such as the sender’s identity, and the emails are not analyzed further.

File Types Used in Attacks

The following table shows the distribution of file types used in attacks.

File Types Used In Attacks

HTML files have taken the top place as the most used file type in email attacks over the month of July. This was primarily because of a reduction in the use of malicious PDF files, which were predominantly used to distribute the Qakbot malware. While the Qakbot malware is still active, during this month, it was not distributed via email-based attacks.

NOTE:If you would like to learn more about Qakbot and botnets, check out the Security Swarm Podcast episode below.

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Other notable changes over the last month include a noticeable increase in malicious archive files and slight increases in the use of Excel files, Word docs, and executable files. With this in mind, we continue to attribute the current low usage of Office documents for payload delivery as a direct result of Microsoft’s decision to disable macros in Office applications by default.

Industry Email Threat Index

The following table shows our Industry Email Threat Index calculated based on the number of threat emails compared to each industry’s clean emails (in median). Different organizations receive a different absolute number of emails. Thus, we calculate the percent share of threat emails from each organization’s threat and clean emails to compare organizations. We then calculate the median of these percent values for all organizations within the same industry to form the industry’s final threat score.

 

Industry Email Threat Index

Most industry verticals saw a net increase in their given threat index for the month of July. To put it simply, the data shows that more threats were levied at (most) businesses than the previous month. Attacks always have an ebb and flow, and even though last month saw a universal decrease in the number of threats, the data is swinging back in the other direction for this data period.

Regarding the top targeted industry, the entertainment sector remains near the top, with research firms seeing a significant increase in the number of attacks in the last 30 days as well. Threat actors know that intellectual property is valuable, so it’s common for research firms to be a heavy target for ransomware and IP theft. Nonetheless, the increased amount of attacks was noticeable.

Impersonated Company Brands and Organizations

The following table shows which company brands and organizations our systems detected most in impersonation attacks.

 

Impersonated Brands

This month’s data also shows that we’ve had some changes in brand impersonation attacks. For example, even though impersonation attempts for DHL saw a net decrease from last month, it remains the most largely impersonated company for these styles of attacks BY FAR. Amazon impersonation attempts saw a noted increase as well. Shipping companies remain high on the list, with an apparent reason for this. Many of us are waiting for a package delivery at any given time. If a threat actor just happens to deliver one of these malicious “shipping emails” to a user’s inbox at just the right time, it’s probable the user may fall victim to the payload. Threat actors see a significant degree of success in this style of attack.

Other notable monthly increases include Sparkasse (German Banking), LinkedIn, Mastercard, and Netflix. Among those increases, nothing has been out of the norm for the last 30 days except a minor spike in Netflix impersonation attacks. Even though there isn’t a high chance of pulling sensitive information, like payment details, out of a target’s Netflix account, threat actors can still leverage the knowledge gained for use in other attacks, such as credential stuffing, or sell access to the Netflix accounts in Darknet forums for lower prices.

Other Interesting Findings in Our Data This Month

Every month we keep a lookout for anything else that’s interesting in our data. This often surfaces new attacks, attack types, and threat-vector variations. During the last month, we’ve identified several cases where a malicious QR code is embedded within an email. While that isn’t out of the ordinary, and we’ve identified increased use of malicious QR codes industry-wide in the past years, there is a stark difference in what we’ve observed in this case.

A typical defense against malicious QR codes (if you don’t have a security vendor that scans them like Hornetsecurity) is to scrutinize the associated URL of the QR code highly. We’ve seen a trend in the last month where threat actors are obfuscating the use of IP addresses within their URLs by making them appear without separated octets. For example, the URL http://194.6.209.34 pointing to the www.hornetsecurity.com web server can also be written as http://3255226658. End users have been somewhat trained to be suspicious of IP addresses. With this formatting, a potentially malicious link may pass this trained practice for some users.

Major Incidents and Industry Events

There are several exciting developments in the cybersecurity news space for the month of July.

Notably, the MOVEit file-transfer software vulnerabilities continue to plague the industry. This attack stems from a collection of SQL injection attacks that enable privilege escalation and unauthorized access to target environments. The most recent vulnerabilities are being tracked as CVE-2023-36934 if you want to read more about it.

The Clop ransomware gang continues to exploit these vulnerabilities, and has even started double-extortion attacks on targets by threatening to leak stolen data if the ransom isn’t paid. Meanwhile, the number of breaches attributed to these vulnerabilities continues to stack up. The affected organizations now include Deloitte, the Hallmark channel, and various government entities.

The use of generative AI in cyber-attacks has continued to evolve over the past month. The Independent has reported that as many as 200k compromised OpenAI accounts are now for sale on the dark web. This is up from the 100k number that we commented on in last month’s report. On top of that, the hacking community has now developed its threat-actor variant of ChatGPT, dubbed WormGPT, which lacks any of the controls or ethical barriers that are present in ChatGPT itself. This highlights that generative AI will continue to change the threat landscape and make launching attacks more accessible to less skilled threat actors.

Our final news item for the week focuses on Microsoft directly. In a July 11th announcement, Microsoft indicated that a Chinese threat-actor designated Storm-0558 had somehow gained access to a Microsoft account consumer signing key. The threat actor then used the stolen signing key to forge authentication tokens that allowed them unauthorized access to data in Exchange Online, and Outlook.com accounts across “approximately 25 organizations” Experts were quick to point out that the potential list of impacted services was likely more than just Exchange Online and Outlook.com. Some commented that the list potentially includes services like SharePoint, OneDrive, and Teams. According to Microsoft, the vulnerability that led to this breach has now been patched.

It’s still early days for this breach, and more information will be forthcoming, but this highlights the growing industry problem of “vendor overdependence”. For those unfamiliar with this concept, it’s the act of utilizing one vendor for an increasing percentage of critical business functions with a potential lack of independent oversight. In this case, you have the same vendor (Microsoft) not only holding onto and providing access to customer production data through services like Microsoft 365 but also the party involved in providing Security for those services. There is a potential conflict of interest.

Arguably, third-party involvement in this recent case wouldn’t have helped, as the breach was due to a vulnerability in Microsoft’s authentication process. Still, the point is that a third party can help keep an objective eye on potential threats. It is generally healthy for the IT security community and businesses to consume services from a major cloud provider.

Predictions for the Coming Months

We predict that malicious use of generative AI will continue to increase and will likely be part of this section of our monthly report for some time. It’s clear that generative AI is the next stage of the ever-present “arms race” between blue teams and threat actors. Knowing that new dark-web-specific generative AI tools are being developed (like WormGPT), it’s reasonable to assume that attacks like Business Email Compromise (BEC) will likely increase. These tools provide the necessary skills and access for lucrative attacks like BEC to threat actors lacking the skills needed.

The fallout from the Storm-0558 Microsoft breach will be a recurring theme as more information comes to light in the coming weeks. The conversation around vendor overdependence and the role of 1st party providers in the cloud will likely come under heavy scrutiny by the community and government entities.

Finally, we suspect persistent threats like Qakbot will continue to evolve. While there are signs that the threat actor behind Qakbot has pivoted to other styles of attacks with lower volume, the threat remains. We will continue to provide updates on persistent email threat actors like Qakbot and Emotet on a month-to-month basis as needed.

Expert Commentary from Hornetsecurity

We asked some of our internal experts about the news from this month. We have posted their responses below!

From Andy Syrewicze, Security Evangelist, on vendor overdependence:

There’s something to be said about a tightly integrated service like M365. I get it, but some service areas should only be provided by the same vendor with heavy oversight. For example, productivity solutions (like M365) and Security. There is an inherent conflict of interest in a vendor selling a solution like M365, which then is also the party responsible for transparent Security. As discussed in a recent episode of the Security Swarm Podcast, there is very little transparency on the state of Security internally within many major cloud platforms, and third-party security providers play a key role in keeping everything transparent and keeping everyone honest. Microsoft seems to have done an OK job in terms of communication with the recent Microsoft Cloud breach, but it’s sure to bring the whole conversation around vendor overdependence back to the fore in the coming weeks, and frankly, it should.

From Jan Bartkowski, Team Lead Security Architecture & Engineering, on the challenges blue teams face with cloud applications:

Security teams face the difficult challenge of monitoring all IT resources their company uses. Monitoring the activity on cloud applications is crucial but often impossible or heavily restricted: Many cloud applications simply do not provide auditing logs or similar options to help identify suspicious behavior. Microsoft’s recent announcement of expanding their logging in the non-E5 plans was overdue. Locking, sometimes even basic security features behind additional required licenses, is a way too common practice that vendors and customers should question to enable security teams.

Monthly Recommendations

Given the current state of the landscape, what are our recommendations for this month?

  • If your organization uses the MOVEit file transfer software and still needs to apply the patches for the recent string of vulnerabilities, please do so ASAP.
  • With email threats increasing across categories this month, now is an excellent time to evaluate your email security posture. Look at the solutions you have in place and ensure the proper rules and mitigations are present. If you’re in need of a solution in this space, we offer a robust and feature-rich solution for email security in our 365 Total Protection suite.
  • With the rise in Business Email Compromise attacks, end users must learn to detect fraudulent emails well. If you still need to invest in security training for your end users, do so now. Like the point above, if you need a solution, we have an effective and time-friendly solution in the Hornetsecurity Security Awareness Service.
  • Even though Microsoft claims the damage from the Storm-0558 breach is contained, check your security and M365 audit logs for suspicious behavior. Ideally, you have a security logging solution, e.g., SIEM, that highlights suspicious user logins and interactions for you. Ensure you have internal processes defined on how to handle security incidents.

About Hornetsecurity

Hornetsecurity is a leading global provider of next-generation cloud-based security, compliance, backup, and security awareness solutions that help companies and organizations of all sizes around the world. Its flagship product, 365 Total Protection, is the most comprehensive cloud security solution for Microsoft 365 on the market. Driven by innovation and cybersecurity excellence, Hornetsecurity is building a safer digital future and sustainable security cultures with its award-winning portfolio. Hornetsecurity operates in more than 30 countries through its international distribution network of 8,000+ channel partners and MSPs. Its premium services are used by more than 50,000 customers.

Monthly Threat Review June 2023

Monthly Threat Review June 2023

QakBot remains a threat, DHL and Crypto Service MetaMask Brand Impersonation on the Rise

Introduction

The Monthly Threat Review by Hornetsecurity brings you monthly insights into M365 security trends, email-based threats, and commentary on current events in the cybersecurity space. This edition of the Monthly Threat Review focuses on data for the month of June.

Executive Summary

  • The overall trend for June vs. May is a decrease in threats. That said, the number of more sophisticated malware campaigns increased.
  • PDF usage as a payload delivery mechanism is up 1.4% over the previous month. Continued use by the Qakbot malware largely drives this.
  • Despite Microsoft’s crackdown on Macros in Office products, using Word and Excel documents for payload delivery has increased. While the attack chain is more difficult now due to Microsoft’s changes, threat actors are successfully using cleverly crafted documents to trick users into copying suspicious files to the Office templates folder, where execution is then allowed.
  • Mining and Entertainment continue to be the current most-targeted industry verticals.
  • We have observed large increases in brand impersonation attacks for DHL, MetaMask, American Express, Strato, and LinkedIn.
  • Multiple SQL injection vulnerabilities in the MOVEit file-transfer application from Progress Software have led to data breaches across countries and industry sectors. Rapid patching and mitigation are STRONGLY recommended.
  • AI continues to be a sore spot for security and privacy across the industry. Compromised OpenAI accounts with logged prompt history could be a potential issue for organizations using privileged information within chat prompts.
  • AI-enabled attacks are predicted to increase and eventually become the norm.

Threat Overview

Unwanted Emails By Category

The following table shows the distribution of unwanted emails per category for June 2023 compared to May 2023.

Unwanted Emails by Category

Overall amounts of traffic in the “Threat”, “AdvThreat”, and “Spam” categories were down for June, while the amount of traffic “Rejected” saw a 5.3% increase for the month.

As a reminder, the “Rejected” category refers to mail that Hornetsecurity services rejected during the SMTP dialog because of external characteristics, such as the sender’s identity or IP address. If a sender is already identified as compromised, the system does not proceed with further analysis. The SMTP server denies the connection right at the initial point of connection based on the negative reputation of the IP and the sender’s identity.

Other categories in the image are described in the table below:

Category Description
Spam These emails are unwanted and are often promotional or fraudulent. The emails are sent simultaneously to a large number of recipients.
Threat These emails contain harmful content, such as malicious attachments or links, or they are sent to commit crimes like phishing.
AdvThreat Advanced Threat Protection has detected a threat in these emails. The emails are used for illegal purposes and involve sophisticated technical means that can only be fended off using advanced dynamic procedures.
Rejected Our email server rejects these emails directly during the SMTP dialog because of external characteristics, such as the sender’s identity, and the emails are not analyzed further.

File Types Used in Attacks

The following table shows the distribution of file types used in attacks.

File Types Used in Attacks

The re-emergence of Qakbot is seen as the primary driver behind the increase in PDF attachments over the last few months. As some other delivery mechanisms, such as DOCX (Word), have become more challenging, PDF remains a popular option for threat actors.

NOTE: If you would like to learn more about Qakbot and botnets, check out the Security Swarm Podcast episode below.

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That said, attackers continue to find ways around Microsoft’s decision to disable macros in Office applications by default. This is usually done by a cleverly crafted header within the malicious document that is made to appear as a legit Office notification. The “notification” instructs the user to move the offending document to the Office templates folder and re-open it. This will typically allow the malicious code to run on the target system.

The difficulties in leveraging office documents for malicious purposes continue to drive the use of other file types for attacks, such as HTML, which use is still relatively high, and disk image files.

Industry Email Threat Index

The following table shows our Industry Email Threat Index calculated based on the number of threat emails compared to each industry’s clean emails (in median). Different organizations receive a different absolute number of emails. Thus, we calculate the percent share of threat emails from each organization’s threat and clean emails to compare organizations. We then calculate the median of these percent values for all organizations within the same industry to form the industry’s final threat score.

Industry Email Threat Index

Overall, the threat is down across the board for June compared to May. This coincides with fewer malicious emails, as shown in the “Unwanted Emails by Category” section above. One potential reason could be that this is the start of the summer holiday season, and threat actors may assume that fewer people are in the office. In addition, fewer compromised devices abused for sending spam and threat emails are online. However, it is important to highlight that the number of more sophisticated malware campaigns, such as QakBot, increased.

Regarding the top targeted industry, the Mining and Entertainment verticals remain the most targeted sector for June, just as in May.

Impersonated Company Brands and Organizations

The following table shows which company brands and organizations our systems detected most in impersonation attacks.

Impersonated Brands

The biggest mover on this list for June is MetaMask, one of the largest crypto wallet providers. An extensive threat-actor campaign (June 27-29) targeted users of the MetaMask Cryptocurrency Wallet service. The goal was to impersonate the brand to access the victim’s crypto wallets and the funds within.

Brand impersonation for DHL, American Express, Strato, LinkedIn, and 1&1 also saw a marked increase over the month compared to May. These all remain popular options for threat actors — especially shipping services such as DHL. With the increase in at-home deliveries in the last couple of years, threat actors know they have a high probability of landing a compelling “shipping email” into users’ mailboxes when they may be expecting a delivery.

Major Incidents and Industry Events

The current major concern in the industry continues to be the fallout from vulnerabilities in the popular file-transfer software MOVEit from Progress Software. While multiple vulnerabilities are at play, the most severe has been categorized as SQL injection attacks that enable privilege escalation and unauthorized access to environments. The most recent CVE for the MOVEit Transfer application is being tracked as CVE-2023-35708. If you use MOVEit and still need to apply the June 15th patch, it is STRONGLY recommended you block traffic to MOVEit via ports 80 and 443.

Despite the danger, many businesses are being caught off guard. There are several organizations that have been impacted by these vulnerabilities, including the New York City Department of Education, Schneider Electric, Siemens Electric, and 122 organizations in total, according to Ars Technica.

Other concerns in the industry continue to center around the use of AI, either via direct use by threat actors to launch AI-enabled attacks or in terms of privacy concerns. The Hacker News recently reported over 100k OpenAI accounts had been stolen and sold on the dark web. Remember that ChatGPT saves a log of all previous prompts and responses. Pair this with the news that there have been several instances of business employees inputting sensitive company data into AI services, and you have a recipe for disaster. Samsung recently fell victim to this problem.

 

Predictions for the Coming Months

While the industry hopes there will be no further fallout from the MOVEit zero-day vulnerability, we expect to hear from more casualties in the following days and weeks. Security researchers and threat actors may test attack patterns against the MOVEit zero-day vulnerability on other popular services to see if it can be applied. Consequently, we may see similar findings affecting other services in the near future as the vulnerability gains attention in the news.

We are also likely to see AI-enabled attacks continue to ramp up. With ChatGPT accounts readily available for purchase on the dark web, we will likely see threat actors continue to utilize it for assistance with attacks. On top of that, we are likely to see cases where sensitive data has been compromised due to stolen ChatGPT accounts and logged prompt data. Stolen sensitive data can be used not only for extortion but also for spearphishing attacks.

On top of all this, the usual threats persist. Qakbot will continue operations. It is uncertain what the current operational status of Emotet is, but it is possible that we could see it reemerge utilizing advanced delivery methods similar to those used by the QakBot malware.  While not as heavily featured in the news as some of the other items mentioned above, the threat of these botnets remains nonetheless.

Expert Commentary from Hornetsecurity

We asked some of our internal experts about the news from this month. We have posted their responses below!

From Andy Syrewicze, Security Evangelist, on AI-Enabled Attacks:

We continue to see cases where threat actors leverage AI for attacks, either for OSINT purposes or for automating a portion of the attack chain. While the doom and gloom of our new AI-fueled world have SOME genuine cause for concern, it’s important to remember that the blue team can also use AI. This includes training, log analysis, machine learning and natural language processing for defensive tools, and LOTS of other possibilities. The arms race between threat actors and blue teams will continue, and blue teams can use AI-powered defensive tools to keep up with threat-actor capabilities.

From Umut Alemdar, Head of Security Lab, on the QakBot malware:

The dynamic and rapidly evolving nature of the QakBot malware poses significant risks to businesses and organizations worldwide. The threat actors behind QakBot changed the delivery techniques multiple times this year to manage to bypass security solutions, and we expect to see more creative approaches in the second half of the year. Hence, investing in advanced protection systems augmented by AI and incident response tools is crucial for businesses today. Additionally, conducting regular cybersecurity awareness training for employees is paramount, as it significantly mitigates the risk of successful filter bypasses and safeguards your organization from costly breaches. A proactive, well-rounded approach to cybersecurity is the key to staying secure.

Monthly Recommendations

Given the current state of the landscape, what are our monthly recommendations?

  • For starters, you can continue to use this monthly report to stay current on the latest email threats and communicate those most relevant to your user base. For example, if your organization uses DHL for regular shipments, communicate the risk of fraudulent DHL emails to the relevant team members.
  • Train your users HEAVILY to scrutinize PDF, Word, and Excel files. We continue to see these files being used for the delivery of payloads. If a user sees one of these file types from an external source, they should be trained to be extra careful with such emails. That said, if you need help training your users along these lines and you are not already a Hornetsecurity customer, be sure to check out our Security Awareness Service for more information.
  • If your organization uses MOVEit by Progress Software, we urge you to install the latest patches. If you still need to install the patches, block traffic to the service on ports 80 and 443 AT A MINIMUM until you can apply the patches. This vulnerability is being actively exploited in the wild, so do not wait.
  • If your organization still needs to discuss how workers should or should not be using AI tools, you should do so ASAP and develop internal policies. Many organizations have lost the governance of sensitive company data when employees use said data inside of an AI prompt. This potential exposure point needs to be addressed with internal policies at a minimum.

About Hornetsecurity

Hornetsecurity is a leading global provider of next-generation cloud-based security, compliance, backup, and security awareness solutions that help companies and organizations of all sizes around the world. Its flagship product, 365 Total Protection, is the most comprehensive cloud security solution for Microsoft 365 on the market. Driven by innovation and cybersecurity excellence, Hornetsecurity is building a safer digital future and sustainable security cultures with its award-winning portfolio. Hornetsecurity operates in more than 30 countries through its international distribution network of 8,000+ channel partners and MSPs. Its premium services are used by more than 50,000 customers.

Email Threat Review November 2022

Email Threat Review November 2022

Executive Summary

  • Emotet started to use social engineering tricks to bypass Microsoft’s recent macro restrictions for documents downloaded from the Internet.

Summary

In this monthly email threat review installment, we present an overview of the email-based threats observed in November 2022 and compare them to the previous month’s threats.

The report provides insights into the following:

Unwanted emails by category

The following table shows the distribution of unwanted emails per category.

Email category %
Rejected 86.29
Spam 10.28
Threat 2.45
AdvThreat 0.98

The following histogram shows the email volume per category per day.

Many rejected emails around 2022-11-14 to 2022-11-16 were related to an extensive periodic reoccurring sextortion scam campaign targeting German-speaking victims.

Methodology

The listed email categories correspond to those listed in the Email Live Tracking of Hornetsecurity’s Control Panel. So our users are already familiar with them. For others, the categories are:

Category Description
Spam These emails are unwanted and are often promotional or fraudulent. The emails are sent simultaneously to a large number of recipients.
Threat These emails contain harmful content, such as malicious attachments or links, or they are sent to commit crimes like phishing.
AdvThreat Advanced Threat Protection has detected a threat in these emails. The emails are used for illegal purposes and involve sophisticated technical means that can only be fended off using advanced dynamic procedures.
Rejected Our email server rejects these emails directly during the SMTP dialog because of external characteristics, such as the sender’s identity, and the emails are not analyzed further.

File types used in attacks

The following table shows the distribution of file types used in attacks.

File type (used in malicious emails) %
HTML 31.3
PDF 25.8
Archive 20.3
Excel 6.7
Executable 5.2
Word 4.1
Disk image files 3.5
Script file 0.5
Other 2.6

Despite the efforts of Microsoft to make Excel documents less attractive for attackers by disabling macros in documents downloaded from the Internet by default, malicious Excel documents made a comeback. The previous month the use of malicious Excel documents in attacks was in decline. However, Emotet started to use Excel macro documents despite Microsoft making it less attractive for attackers by combining it with a social engineering attack to bypass Microsoft’s mitigation. We outline this social engineering component in the highlighted threat email campaigns section.

Industry Email Threat Index

The following table shows our Industry Email Threat Index calculated based on the number of threat emails compared to each industry’s clean emails (in median).

Industries Share of threat in threat and clean emails
Research industry 3.9
Manufacturing industry 3.6
Mining and metal industry 3.5
Transport industry 3.4
Utilities 3.3
Automotive industry 3.1
Entertainment industry 3.0
Healthcare industry 3.0
Agriculture industry 2.9
Information technology industry 2.7

The following bar chart visualizes the email-based threat posed to each industry.

Methodology

Different (sized) organizations receive a different absolute number of emails. Thus, we calculate the percent share of threat emails from each organization’s threat and clean emails to compare organizations. We then calculate the median of these percent values for all organizations within the same industry to form the industry’s final threat score.

Attack techniques

The following table shows the attack techniques used in attacks.

Attack technique %
Phishing 26.2
URL 14.2
Extortion 6.3
Advance-fee scam 4.8
HTML 3.0
Executable in archive/disk-image 2.7
Impersonation 2.5
Maldoc 1.7
PDF 0.6
Other 38.0

The following histogram shows the email volume per attack technique used per hour.

Impersonated company brands and organizations

The following table shows which company brands and organizations our systems detected most in impersonation attacks.

Impersonated brand or organization %
DHL 12.8
Postbank 9.4
Amazon 9.4
Sparkasse 7.1
LinkedIn 3.9
Microsoft 3.2
DocuSign 3.0
Strato 2.8
Fedex 2.6
Other 45.8

The following histogram shows the email volume for brands and organizations detected in impersonation attacks per hour.

Highlighted threat email campaigns

Previously many attackers, including the threat actors behind Emotet, stopped using macro documents. This is likely because Microsoft started disabling macros from documents downloaded from the Internet in their Office products per default. Attackers used other malicious files such as shortcut files (.lnk) or HTML files instead. Despite this, Emotet started to use malicious macros in Excel documents again this month. They used email conversation thread hijacking attacks as well as generic emails. However, the attached malicious Excel documents contain social engineering to bypass the macro restrictions imposed on documents downloaded from the Internet. To this end, the malicious document will tell the victim to copy the document to the Microsoft Office Templates folder. This Templates folder is a trusted location from which Microsoft Office will allow macros in the document again.

Like older Emotet macro documents, the macros will download the Emotet malware and execute it on the victim’s system.

Methodology

Hornetsecurity observes thousands of threat email campaigns of varying threat actors ranging from unsophisticated low-effort attacks to highly complex obfuscated attack schemes. Our highlighting includes only a subset of those threat email campaigns.

Email Threat Review November 2022

Email Threat Review October 2022

Summary

In this monthly email threat review installment, we present an overview of the email-based threats observed in October 2022 and compare them to the previous month’s threats.

The report provides insights into the following:

Unwanted emails by category

The following table shows the distribution of unwanted emails per category.

Email category %
Rejected 78.73
Spam 15.41
Threat 4.17
AdvThreat 1.64
Content 0.05

The following histogram shows the email volume per category per day.

Methodology

The listed email categories correspond to those listed in the Email Live Tracking of Hornetsecurity’s Control Panel. So our users are already familiar with them. For others, the categories are:

Category Description
Spam These emails are unwanted and are often promotional or fraudulent. The emails are sent simultaneously to a large number of recipients.
Content These emails have an invalid attachment. The administrators define in the Content Control module which attachments are invalid.
Threat These emails contain harmful content, such as malicious attachments or links, or they are sent to commit crimes like phishing.
AdvThreat Advanced Threat Protection has detected a threat in these emails. The emails are used for illegal purposes and involve sophisticated technical means that can only be fended off using advanced dynamic procedures.
Rejected Our email server rejects these emails directly during the SMTP dialog because of external characteristics, such as the sender’s identity, and the emails are not analyzed further.

File types used in attacks

The following table shows the distribution of file types used in attacks.

File type (used in malicious emails) %
HTML 27.8
Archive 24.9
PDF 16.6
Disk image files 7.9
Excel 6.5
Executable 5.0
Word 4.4
Script file 0.9
Other 5.9

The following histogram shows the email volume per file type used in attacks per 7 days.

Industry Email Threat Index

The following table shows our Industry Email Threat Index calculated based on the number of threat emails compared to each industry’s clean emails (in median).

Industries Share of threat in threat and clean emails
Mining and metal industry 4.5
Manufacturing industry 4.0
Healthcare industry 3.9
Automotive industry 3.8
Research industry 3.7
Transport industry 3.6
Media industry 3.6
Utilities 3.5
Entertainment industry 3.4
Information technology industry 3.4

The following bar chart visualizes the email-based threat posed to each industry.

Methodology

Different (sized) organizations receive a different absolute number of emails. Thus, we calculate the percent share of threat emails from each organization’s threat and clean emails to compare organizations. We then calculate the median of these percent values for all organizations within the same industry to form the industry’s final threat score.

Attack techniques

The following table shows the attack techniques used in attacks.

Attack technique %
Phishing 27.8
URL 10.8
Advance-fee scam 7.1
Executable in archive/disk-image 3.8
Extortion 3.5
HTML 2.3
Impersonation 1.0
Maldoc 0.8
PDF 0.1
Other 42.7

The following histogram shows the email volume per attack technique used per hour.

Impersonated company brands and organizations

The following table shows which company brands and organizations our systems detected most in impersonation attacks.

Impersonated brand or organization %
Sparkasse 29.8
DHL 14.3
Amazon 12.7
Metamask 2.5
Santander 2.4
LinkedIn 2.1
Microsoft 2.1
Intuit 1.7
1&1 1.7
PayPal 1.3
Strato 1.2
Mastercard 1.2
Fedex 1.2
American Express 1.1
UPS 1.1
Barclays Bank 1.0
Royal Bank of Canada 1.0
HSBC 1.0
Other 20.6

The following histogram shows the email volume for brands and organizations detected in impersonation attacks per hour.

This month we detected several phishing emails impersonating MetaMask (a software cryptocurrency wallet used to interact with the Ethereum blockchain). On 2022-10-31, the most extensive detected campaign impersonating MetaMask. MetaMask thus enters this month’s top impersonated brands ranking in 4th place.

Highlighted threat email campaign

This month the threat actors distributing the QakBot malware via email conversation thread hijacking attacks started to alter the subjects of the stolen emails they send replies to. We believe this is done to impede analysis.

In an email conversation thread hijacking attack, the threat actors steal emails from victims and then reply to these emails with the original email conversation and subject being quoted in the fake reply email. These emails are often hard to spot in legitimate email traffic because they use legitimate email subjects and stolen content. However, if the attackers use the same stolen email multiple times for such reply attacks, an administrator in an attacked company could find other attack emails by searching for the same subject. To prevent this, the threat actors behind the QakBot malware campaign with bot ID BBxx started to insert repeat characters in their stolen email subjects.

In the following examples, we see emails whose original subject was Erinnerung (the German word for Reminder). The actors used this stolen email to form multiple attack emails by changing the subject to Erinnerrunng, Erinnneerrungg, and Erinnnerruung by randomly doubling characters in the subject. The lower part in each email is quoted from the original stolen email and is not altered like the subject.

Email Threat Review November 2022

Email Threat Review September 2022

Executive Summary

  • HTML is now the most used file type in email attacks with attachments.

Summary

In this monthly email threat review installment, we present an overview of the email-based threats observed in September 2022 and compare them to the previous month’s threats.

The report provides insights into the following highlights:

Unwanted emails by category

The following table shows the distribution of unwanted emails per category.

Email category %
Rejected 78.25
Spam 15.75
Threat 3.91
AdvThreat 2.04
Content 0.04

The following histogram shows the email volume per category per day.

Methodology

The listed email categories correspond to those listed in the Email Live Tracking of Hornetsecurity’s Control Panel. So our users are already familiar with them. For others, the categories are:

Category Description
Spam These emails are unwanted and are often promotional or fraudulent. The emails are sent simultaneously to a large number of recipients.
Content These emails have an invalid attachment. The administrators define in the Content Control module which attachments are invalid.
Threat These emails contain harmful content, such as malicious attachments or links, or they are sent to commit crimes like phishing.
AdvThreat Advanced Threat Protection has detected a threat in these emails. The emails are used for illegal purposes and involve sophisticated technical means that can only be fended off using advanced dynamic procedures.
Rejected Our email server rejects these emails directly during the SMTP dialog because of external characteristics, such as the sender’s identity, and the emails are not analyzed further.

File types used in attacks

The following table shows the distribution of file types used in attacks.

File type (used in malicious emails) %
HTML 31.1
Archive 23.0
PDF 12.3
Word 10.2
Disk image files 8.2
Executable 4.2
Excel 3.7
Script file 3.2
Other 4.0

The following histogram shows the email volume per file type used in attacks per 7 days.

This month, HTML attachments have become the most commonly used file type in attacks with attachments. Excel macro documents are still in decline.

Industry Email Threat Index

The following table shows our Industry Email Threat Index calculated based on the number of threat emails compared to each industry’s clean emails (in median).

Industries Share of threat in threat and clean emails
Research industry 6.0
Media industry 4.9
Manufacturing industry 4.6
Mining and metal industry 4.6
Entertainment industry 4.2
Healthcare industry 4.1
Retail industry 4.1
Construction industry 4.1
Information technology industry 3.9
Utilities 3.8

The following bar chart visualizes the email-based threat posed to each industry.

With an Industry Email Threat Index of 6.0, the research industry remains at the top position. The education industry, which ranked 3rd last month, fell sharply from 4.3 to 3.8, thus not making the top 10 anymore. The mining and metal industry saw a significant increase from 3.4 to 4.6, making it enter the top 10 at place four from the previous month’s 14th place.

Overall the Email Threat Index across all industries increased compared to last month. This is expected as the summer month with summer holidays usually causes a drop in threat emails sent.

Methodology

Different (sized) organizations receive a different absolute number of emails. Thus, we calculate the percent share of threat emails from each organization’s threat and clean emails to compare organizations. We then calculate the median of these percent values for all organizations within the same industry to form the industry’s final threat score.

Attack techniques

The following table shows the attack techniques used in attacks.

Attack technique %
Phishing 26.3
URL 9.9
Advance-fee scam 6.1
Extortion 4.2
Executable in archive/disk-image 3.5
HTML 2.1
Impersonation 1.1
Maldoc 0.7
PDF 0.1
Other 46.2

The following histogram shows the email volume per attack technique used per hour.

Impersonated company brands and organizations

The following table shows which company brands and organizations our systems detected most in impersonation attacks.

Impersonated brand or organization %
Sparkasse 35.7
DHL 11.1
Amazon 7.1
Santander 3.9
Royal Bank of Canada 3.2
LinkedIn 2.3
Fedex 1.9
1&1 1.8
Postbank 1.7
Targobank 1.5
UPS 1.3
Microsoft 1.3
Commerzbank 1.2
HSBC 1.2
Intuit 1.1
American Express 1.0
Other 23.7

The following histogram shows the email volume for brands and organizations detected in impersonation attacks per hour.

Highlighted threat email campaigns

Around 2022-09-24, we observed a large-scale phishing campaign impersonating the Royal Bank of Canada.

Email Threat Review November 2022

Email Threat Review August 2022

Contents

In this monthly email threat review instalment, we present an overview of the email-based threats observed in August 2022 and compare them to the previous month’s threats.

The report provides insights into:

Unwanted emails by category

The following table shows the distribution of unwanted emails per category.

Email category %
Rejected 81.01
Spam 14.03
Threat 3.29
AdvThreat 1.62
Content 0.04

The following histogram shows the email volume per category per day.

Methodology

The listed email categories correspond to those listed in the Email Live Tracking of Hornetsecurity’s Control Panel. So our users are already familiar with them. For others, the categories are:

Category Description
Spam These emails are unwanted and are often promotional or fraudulent. The emails are sent simultaneously to a large number of recipients.
Content These emails have an invalid attachment. The administrators define in the Content Control module which attachments are invalid.
Threat These emails contain harmful content, such as malicious attachments or links, or they are sent to commit crimes like phishing.
AdvThreat Advanced Threat Protection has detected a threat in these emails. The emails are used for illegal purposes and involve sophisticated technical means that can only be fended off using advanced dynamic procedures.
Rejected Our email server rejects these emails directly during the SMTP dialogue because of external characteristics, such as the sender’s identity, and the emails are not analyzed further.

File Types used in Attacks

The following table shows the distribution of file types used in attacks.

File type (used in malicious emails) %
Word 26.1
HTML 22.2
Archive 20.7
PDF 12.5
Disk image files 7.2
Executable 4.2
Excel 4.0
Script file 0.7
Other 2.5

The following histogram shows the email volume per file type used in attacks per 7 days.

HTML attachments used in attacks increased further from 14.8% to 22.2%. As of last month, we attribute this increase to Microsoft’s recent changes to disable Macros in Microsoft Office documents by default. Excel files continued to decrease from 5.1% to 4.0%.

The increase in Word documents used in attacks from 5.1% to 26.1% can mainly be attributed to a malicious email campaign using an RTF attachment exploiting the CVE-2018-0798 vulnerability to distribute the Snake Keylogger malware. Most of the emails were sent to a minimal number of recipients, with several hundred thousand duplicate emails of this campaign being sent to each such recipient. All of which Hornetsecurity’s filters detected and quarantined, of course.

Industry Email Threat Index

The following table shows our Industry Email Threat Index calculated based on the number of threat emails compared to each industry’s clean emails (in median).

Industries Share of threat in threat and clean emails
Research industry 5.8
Transport industry 4.7
Education industry 4.3
Manufacturing industry 4.2
Entertainment industry 4.1
Media industry 4.1
Utilities 3.9
Retail industry 3.7
Healthcare industry 3.7
Construction industry 3.6

The following bar chart visualizes the email-based threat posed to each industry.

The overall Industry Email Threat Index increased slightly from last month. The research industry increased over-proportionally from 4.8% to 5.8%. Another significant increase could be measured in the education industry, which increased from 3.6% to 4.3%, from 8th to 3rd place.

Methodology

Different (sized) organizations receive a different absolute number of emails. Thus, we calculate the per cent share of threat emails from each organization’s threat and clean emails to compare organizations. We then calculate the median of these per cent values for all organizations within the same industry to form the industry’s final threat score.

Attack Techniques

The following table shows the attack techniques used in attacks.

Attack technique %
Phishing 29.2
URL 11.4
Advance-fee scam 9.2
Extortion 5.0
Maldoc 3.6
Executable in archive/disk-image 3.6
HTML 2.2
Impersonation 1.1
PDF 0.7
Other 34.0

The following histogram shows the email volume per attack technique used per hour.

The spike in attacks using malicious documents (maldocs) can be attributed to the previously discussed emails using an RTF attachment exploiting the CVE-2018-0798 vulnerability to distribute the Snake Keylogger malware.

Impersonated Company Brands and Organizations

The following table shows which company brands and organizations our systems detected most in impersonation attacks.

Impersonated brand or organization %
Sparkasse 33.4
DHL 9.9
Amazon 8.8
Postbank 3.7
LinkedIn 3.3
UPS 3.1
HSBC 2.3
Dropbox 1.8
1&1 1.8
DocuSign 1.7
Strato 1.4
Santander 1.4
Intuit 1.3
Microsoft 1.3
Fedex 1.2
Other 23.6

The following histogram shows the email volume for brands and organizations detected in impersonation attacks per hour.

It’s a constant stream of phishing and other attacks impersonating big brands and organizations to entice recipients to open emails.