ServHelper Backdoor

ServHelper is a newly observed Delphi-based backdoor believed to have been created by the TA505 advanced persistent threat group. It appears to be in active development, with new variants published every few days.

Threat ID:: CC-2880
Category:: Backdoor
Threat Severity:: Medium
Threat Vector:: Phishing
Published:: 14 January 2019 12:00 AM

Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

Affected platforms

The following platforms are known to be affected:

Microsoft Windows

Microsoft Windows - All versions

Threat details

It is delivered via malicious macros distributed in DOC, PUB, PDF and WIZ files in phishing campaigns. When opened, these will download and install ServHelper. Some variants will use links to file-hosting platforms in place of macros.

Once installed, will connect to a command and control server before awaiting further commands. Newer variants will also attempt to establish an SSH tunnel through port 3389 and can monitor web browser profiles on affected devices.

Remediation steps

Type	Step
	To prevent and detect an infection, ensure that: 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. Regular anti-virus and security scans are performed on your organisation’s estate. 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.

Type

Step

To prevent and detect an infection, ensure that:

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.
Regular anti-virus and security scans are performed on your organisation’s estate.
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: 14 February 2020 2:49 pm