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Turla Mail Client Backdoor

Security researchers have discovered a backdoor tool created by the Turla advanced persistent threat group to target mail clients.
Threat ID:
CC-2635
Category:
Trojan
Threat Severity:
Medium
Threat Vector:
Published:
29 August 2018 12:00 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

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This article no longer conforms to NHS Digital's standards for cyber alerts, and may contain outdated or inaccurate information. Use of this information contained in this page is at your own risk

Summary

Security researchers have discovered a backdoor tool created by the Turla advanced persistent threat group to target mail clients.

Threat details

The researchers believe that the tool has been in the wild since at least 2013, although it is possible it was created in 2009.

The backdoor is a self-contained DLL file that is able to install and operate itself on the targeted client. As such, it can be delivered by several Turla tools or by any other malware that is able to execute additional processes.

Once installed, the tool is able to intercept all email traffic, including metadata, from the affected client. It can also to execute commands and programs, exfiltrate data and download additional malware. The tool communicates with its command and control infrastructure using encoded emails, with new files being delivered as PDF attachments. These emails are kept hidden to prevent detection by the user.

For further information

Remediation advice

To prevent and detect an infection, ensure that:

Remediation steps

Type Step
  • A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails.
  • All operating systems, anti-virus and other security products are kept up-to-date.
  • All day-to-day computer activities such as email and internet are performed using non-administrative accounts.
  • Strong password policies are in place.
  • Network, proxy and firewall logs should be monitored for suspicious activity.
  • User accounts accessed from affected devices should be reset on a clean computer.
  • Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security.

Last edited: 17 February 2020 12:55 pm