Xbash Worm

Xbash is a newly observed worm targeting exposed servers worldwide. Written in Python using code taken from the NotPetya malware.

Threat ID:: CC-2675
Category:: Worm
Threat Severity:: Medium
Threat Vector:: Exploit, Insecure network
Published:: 19 September 2018 12:00 AM

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Summary

Xbash is a newly observed worm targeting exposed servers worldwide. Written in Python using code taken from the NotPetya malware.

Affected platforms

The following platforms are known to be affected:

Linux

Linux - Most major distributions
Microsoft Windows Server - All versions

Microsoft Windows Server

Threat details

it is believed to have been created by the Iron Group advanced persistent threat (also known as Rocke) and is being used as both a cryptocurrency miner and ransomware.

Unlike most other worm malware, Xbash will scan for public domains - as well as IP addresses - using target lists downloaded from a command and control (C2) server. Once an open port has been discovered, it will attempt to gain access either through brute-force attacks, default credentials or by exploiting known vulnerabilities in the ActiveMQ, Hadoop or Redis services.

Once it has gained access to a target device, Xbash will check the operating system before further deployment. On Linux systems it will attempt to delete all MongoDB, MySQL and PostgreSQL databases (except for those that contain login information) before creating new databases containing the ransom note. On Windows machines it will connect to a dynamic URL to download a JavaScript or VBScript module, that will then initiate a PowerShell script to install a variant of the XMRig cryptocurrency miner. Both versions will connect to a C2 server before scanning for new targets.

Xbash also has the ability to traverse the local network of any affected device, however, this functionality has not yet been enabled.

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. 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

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 12:58 pm