Researchers have identified yet more high-profile organisations attacked by spying Chinese hackers after seizing hold of the miscreants' command-and-control servers.
Dell SecureWorks Counter Threat Unit (CTU) said that its tactic of "sinkholing" spyware-controlled systems is great for identifying custom malware and warning victims. It typically involves taking over the criminals' domain names to trick their armies of malware-infected computers - known as botnets - into communicating with the researchers' servers. While holding the reins, security experts can study a botnet, find out what sort of snooping the malware is capable of, learn more about its masters and potentially disrupt its villainous activities.
According to Dell SecureWorks, the technique has shed a light on several highly targeted espionage efforts that might otherwise have gone undetected. Victims include a US university conducting military research, we're told.
Sinkholing is not new in computer security: Dell SecureWorks applied it against the Kelihos spam-spewing botnet last year and Polish researchers applied it against Virut last month, for example. Using the tactic against groups dubbed advanced persistent threats (APTs) is a new twist, however: multiple botnets, each using a different Trojan or virus strain to infect machines, could be sharing the same command server.
"You may know eight malware facilities but by sink-holing an APT domain you can find out about another two," explained Silas Cutler, a security researcher at Dell SecureWorks CTU.
This information can be useful in linking malware families based on the shared infrastructure that attackers use to control the infected computers as well as providing proof that an entire network has been compromised.
Ordinary cybercrooks caught using cyber-espionage tools
Dell SecureWorks has linked 300 different families of malware to cyber-espionage attacks. And it's clear that conventional online crooks are using malware primarily designed for cyber-espionage for their own nefarious purposes, such as attacks apparently aimed at stealing online gaming login IDs.
One case identified by Dell SecureWorks uncovered evidence that Protux - a software nasty first detected in spear-phishing expeditions against Tibetan activists in 2008 and attacks against US government agencies - was used in an attack primarily geared against Indian ISP customers. Sinkholing three expired web domains associated with Protux revealed that two of the addresses had been used for regular cybercrime while another was employed in a much more limited and targeted espionage project.
Joe Stewart, director of malware research at Dell SecureWorks CTU, explained that in most cases security researchers take control of a hacker's domain because it either expired or was seized in an internet property ownership dispute. Domains used in APT campaigns sometimes mimic those of the industrial firms and others they target.