Cybercriminals target 40 countries using “invisible” malware

Kaspersky Lab experts have discovered a series of “invisible” targeted attacks that use only legitimate software: widely available penetration-testing and administration tools as well as the PowerShell framework for task automation in Windows – dropping no malware files onto the hard drive, but hiding in the memory.

At the end of 2016, Kaspersky Lab experts were contacted by banks in CIS which had found the penetration-testing software, Meterpreter, now often used for malicious purposes, in the memory of their servers when it was not supposed to be there. The combined tools had been adapted into malicious code that could hide in the memory, invisibly collecting the passwords of system administrators so that the attackers could remotely control the victim’s systems. The ultimate goal appears to have been access to financial processes.

It has been discovered that these attacks are happening on a massive scale: hitting more than 140 enterprise networks in a range of business sectors, with most victims located in the USA, France, Ecuador, Kenya, the UK and Russia.

In total, infections have been registered in 40 countries. It is not known who is behind the attacks. The use of open source exploit code, common Windows utilities and unknown domains makes it almost impossible to determine the group responsible – or even whether it is a single group or several groups sharing the same tools. Known groups that have the most similar approaches are GCMAN and Carbanak.

“The determination of attackers to hide their activity and make detection and incident response increasingly difficult explains the latest trend of anti-forensic techniques and memory-based malware. That is why memory forensics is becoming critical to the analysis of malware and its functions. In these particular incidents, the attackers used every conceivable anti-forensic technique; demonstrating how no malware files are needed for the successful exfiltration of data from a network, and how the use of legitimate and open source utilities makes attribution almost impossible,” said Sergey Golovanov, Principal Security Researcher at Kaspersky Lab.

The attackers are still active, so it is important to note that detection of such an attack is possible only in RAM, the network and registry – and that, in such instances, the use of Yara rules based on a scan of malicious files are of no use.

Staff Writer