ACBackdoor Backdoor

First observed in early September 2019, ACBackdoor is a multi-platform backdoor targeting Windows and Linux systems.

Threat ID:: CC-3293
Category:: Backdoor
Threat Severity:: Medium
Threat Vector:: Download, Insecure network, Exploit
Published:: 20 November 2019 12:00 AM

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

Summary

First observed in early September 2019, ACBackdoor is a multi-platform backdoor targeting Windows and Linux systems.

Affected platforms

The following platforms are known to be affected:

Microsoft Windows

Microsoft Windows - All versions
Linux - Most distributions

Threat details

At the time of publication, it is unclear how the Linux variant of ACBackdoor is distributed, although there are unconfirmed reports indicating it may be delivered manually as an ELF file by attackers. The Windows variant appears to be delivered via small malvertising campaigns using the Fallout exploit kit.

ACBackdoor variants display different capabilities, with the Linux version showing a higher level of sophistication. Upon installation, both variants will attempt to collect user and system information, send this information to a command and control server over HTTPS as Base64 encoded strings, and maintain persistence (via Windows registry entries or symlinking a new initrd file). ACBackdoor Windows variants are able to download and install secondary payloads on affected systems, whilst Linux variants can also extract files and execute shell commands.

For further information:

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.

CVE Vulnerabilities

CVE-2018-8174

Last edited: 11 January 2022 1:36 pm