Feeds

Manic malware Mayhem spreads through Linux, FreeBSD web servers

And how Google could cripple infection rate in a second

Internet Security Threat Report 2014

Malware dubbed Mayhem is spreading through Linux and FreeBSD web servers, researchers say. The software nasty uses a grab bag of plugins to cause mischief, and infects systems that are not up to date with security patches.

Andrej Kovalev, Konstantin Ostrashkevich and Evgeny Sidorov, who work at Russian internet portal Yandex, discovered the malware targeting *nix servers. They traced transmissions from compromised computers to two command and control (C&C) servers. So far they have found 1,400 machines that have fallen to the code, with potentially thousands more to come.

"In the *nix world, autoupdate technologies aren't widely used, especially in comparison with desktops and smartphones. The vast majority of web masters and system administrators have to update their software manually and test that their infrastructure works correctly," the trio wrote in a technical report for Virus Bulletin.

"For ordinary websites, serious maintenance is quite expensive and often webmasters don't have an opportunity to do it. This means it is easy for hackers to find vulnerable web servers and to use such servers in their botnets."

Mayhem spreads by finding servers hosting websites with a remote file inclusion (RFI) vulnerability – it even uses Google's /humans.txt to test for this. If the ad giant rewrote this file, specifically changing the words "we can shake", Mayhem infections would be slowed – until its rfiscan.so plugin is updated.

Once the malware exploits an RFI, or some other weakness, to run a PHP script on a victim, it drops a shared object called libworker.so onto the infected system and pings its C&C servers.

It then creates a hidden file system, usually called sd0, and downloads eight plugins, none of which were picked up by the VirusTotal malware scanning tool.

These include a couple of brute-force password crackers targeting FTP, Wordpress and Joomla accounts – presumably to spread the malware further – and information-gathering web crawlers, one of which hunts for other sites with RFI holes.

Some of the vulnerable web applications Mayhem scans for ... click for slightly larger version (Credit: Kovalev, Otrashkevich, Sidorov)

The Yandex trio warn there may be other plugins in circulation, based on data found on the two cracked C&C servers. These include a tool specifically to exploit systems that haven't patched the Heartbleed vulnerability in OpenSSL.

The team notes that the Mayhem code does bear several similarities to the Trololo_mod and Effusion families of malware, which target Apache and Nginx servers respectively. They recommend system administrators check their servers to make sure Mayhem's spread is limited. ®

Internet Security Threat Report 2014

More from The Register

next story
Azure TITSUP caused by INFINITE LOOP
Fat fingered geo-block kept Aussies in the dark
NASA launches new climate model at SC14
75 days of supercomputing later ...
Yahoo! blames! MONSTER! email! OUTAGE! on! CUT! CABLE! bungle!
Weekend woe for BT as telco struggles to restore service
You think the CLOUD's insecure? It's BETTER than UK.GOV's DATA CENTRES
We don't even know where some of them ARE – Maude
DEATH by COMMENTS: WordPress XSS vuln is BIGGEST for YEARS
Trio of XSS turns attackers into admins
BOFH: WHERE did this 'fax-enabled' printer UPGRADE come from?
Don't worry about that cable, it's part of the config
Cloud unicorns are extinct so DiData cloud mess was YOUR fault
Applications need to be built to handle TITSUP incidents
Astro-boffins start opening universe simulation data
Got a supercomputer? Want to simulate a universe? Here you go
prev story

Whitepapers

Choosing cloud Backup services
Demystify how you can address your data protection needs in your small- to medium-sized business and select the best online backup service to meet your needs.
Getting started with customer-focused identity management
Learn why identity is a fundamental requirement to digital growth, and how without it there is no way to identify and engage customers in a meaningful way.
5 critical considerations for enterprise cloud backup
Key considerations when evaluating cloud backup solutions to ensure adequate protection security and availability of enterprise data.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
How to simplify SSL certificate management
Simple steps to take control of SSL certificates across the enterprise, and recommendations centralizing certificate management throughout their lifecycle.