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Shellbot Remote Access Trojan

rel="nofollow">remote access trojan primarily used as a backdoor and downloader for other malware.
Threat ID:
CC-2729
Category:
Trojan
Threat Severity:
Medium
Threat Vector:
Exploit, Insecure network
Published:
16 October 2018 12:00 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

This content has been archived

This article no longer conforms to NHS Digital's standards for cyber alerts, and may contain outdated or inaccurate information.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

rel="nofollow">remote access trojan primarily used as a backdoor and downloader for other malware.

Threat details

Despite its age, Shellbot continues to be a popular choice for threat actors and is now being used in cryptocurrency mining campaigns against Drupal web servers.

Shellbot is distributed using exploits for two Drupal vulnerabilities to gain access; CVE-2018-7600 (also known as Drupalgeddon 2.0) and CVE-2018-7602. Potentially vulnerable websites are first identified using automated scans, before the exploits are deployed to gain access to the underlying server.

Once this is done, Shellbot will use CVE-2018-7600 to escalate its privileges before connecting to a command and control server over IRC. It will then detect and terminate all cryptocurrency mining applications on the server before installing it's own miner. Shellbot is also able to use the infected server in spam and phishing campaigns, to perform distributed denial-of-service attacks and to scan for new devices to infect.

Threat updates

Date Update
1 Nov 2018

Shellbot has recently been utilised by a hacking group called Outlaw. The group distributes Shellbot by exploiting CVE-2006-5973 in the Dovecot email server and CVE-2017-1000117 on Linux servers and internet of things (IoT) devices.

For further information:

Remediation steps

Type Step

Drupal released updates to address both CVE-2018-7600 and CVE-2018-7602 earlier this year. Affected organisations should apply these updates immediately if they have not already done so. The NCSC Web Check tool can be used to identify vulnerable Drupal installations.

Additionally, 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: 17 February 2020 12:54 pm