Government and corporate Windows PCs were among the ranks of a 1.9 million botnet recently discovered by net security firm Finjan.
Finjan security researchers discovered the control server of the botnet after tracing back an infection from a corporate client. Evidence on the cybercrime server, which was hosted in the Ukraine, showed it had been in use since February 2009, and controlled by a cybergang of six people.
Trojan downloader malware planted on insecure websites was used to distribute the malware that seeded the botnet, via drive-by download attacks. The core group of cybercrooks were assisted by a vast affiliate network.
Yuval Ben-Itzhak, chief technology officer at Finjan, said the malware that created the botnet used a variety of Internet Explorer, Firefox and PDF vulnerabilities to spread. He added that only four out of 39 anti-virus scanners detected the malware.
Ben-Itzhak told El Reg that the cybercrooks behind the botnet made their money by auctioning off access to compromised machines through underground forums, typically charging $100 for 1,000 machines. The miscreants almost made money from selling data looted from compromised machines, he added.
The cybercrooks collectively compromised computers in 77 government-owned domains (.gov) from the UK, US and various other countries.
The malware that featured in the attack allowed hackers complete control of compromised PCs, nearly all of which were running Windows XP. A variety of malicious actions, from reading emails to copying files, keystroke logging, and spam distribution were all possible.
Since discovering the botnet, Finjan has supplied information to the server to UK and US law enforcement agencies. The command server is now out of commission. Finjan has informed affected corporate and government agencies about infected computer names, in a move that will hopefully result in a clean-up operation.
Screenshots taken from the command and control server, and more discussion on the superbotnet can be found on Finjan’s blog here. ®