Feeds

World's stealthiest rootkit gets a makeover

Now, TDL4 harder than ever to eradicate

Next gen security for virtualised datacentres

One of the world's more advanced pieces of malware has just gotten a makeover that could make it even more resistant to takedown efforts, security researchers said.

An analysis of recent updates to the TDL4 rootkit, which is also known as TDSS and Alureon, shows that components including its kernel-mode driver and user-mode payload have been rewritten from scratch, researchers from antivirus provider ESET blogged earlier this week. The code overhaul may mean that operators of TDL4, which is used to force keyloggers, adware, and other malicious programs onto compromised machines, may have started providing services to other crimeware groups.

The makeover includes changes to the way TDL4 attempts to remain undetected by antivirus programs and other defenses. Newer versions create a hidden partition at the end of the infected machine's hard disk and set it to active. This ensures that malicious code stashed in it is executed before the Windows operating system is run.

It also protects the code from being removed. The partition is equipped with an advanced file system that checks the integrity of TDL4 components. If any of the files are corrupted, they're removed.

Not that TDL4 wasn't already among the most sophisticated pieces of crimeware available. When it emerged in 2008, it was virtually undetectable by most AV programs, and its use of low-level instructions made it hard for researchers to conduct reconnaissance on it. Its built-in encryption prevents network monitoring tools from monitoring communications sent between infected PCs and command and control servers.

It was among the first rootkits to infect 64-bit versions of Windows by bypassing the OS's kernel mode code signing policy. That protection was introduced into 64-bit versions of Windows and allows drivers to be installed only when they have been digitally signed by a trusted source. In June, researchers at AV provider Kaspersky said TDL4 had infected more than 4.5 million PCs in just three months.

TDL4 also has the ability to communicate over the Kad peer-to-peer network and to infect a the master boot record of a compromised PC's hard drive.

The latest changes suggest that the relentless innovation of those developing TDL4 shows no signs of slowing. ®

The essential guide to IT transformation

More from The Register

next story
Goog says patch⁵⁰ your Chrome
64-bit browser loads cat vids FIFTEEN PERCENT faster!
Chinese hackers spied on investigators of Flight MH370 - report
Classified data on flight's disappearance pinched
KER-CHING! CryptoWall ransomware scam rakes in $1 MEEELLION
Anatomy of the net's most destructive ransomware threat
NIST to sysadmins: clean up your SSH mess
Too many keys, too badly managed
Scratched PC-dispatch patch patched, hatched in batch rematch
Windows security update fixed after triggering blue screens (and screams) of death
Researchers camouflage haxxor traps with fake application traffic
Honeypots sweetened to resemble actual workloads, complete with 'secure' logins
prev story

Whitepapers

Top 10 endpoint backup mistakes
Avoid the ten endpoint backup mistakes to ensure that your critical corporate data is protected and end user productivity is improved.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Backing up distributed data
Eliminating the redundant use of bandwidth and storage capacity and application consolidation in the modern data center.
The essential guide to IT transformation
ServiceNow discusses three IT transformations that can help CIOs automate IT services to transform IT and the enterprise
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.