The online attack service launched late last year by the same criminals who knocked Sony and Microsoft’s gaming networks offline over the holidays is powered mostly by thousands of hacked home Internet routers, KrebsOnSecurity.com has discovered.
Just days after the attacks on Sony and Microsoft, a group of young hoodlums calling themselves the Lizard Squad took responsibility for the attack and announced the whole thing was merely an elaborate commercial for their new “booter” or “stresser” site — a service designed to help paying customers knock virtually any site or person offline for hours or days at a time. As it turns out, that service draws on Internet bandwidth from hacked home Internet routers around the globe that are protected by little more than factory-default usernames and passwords.
In the first few days of 2015, KrebsOnSecurity was taken offline by a series of large and sustained denial-of-service attacks apparently orchestrated by the Lizard Squad. As I noted in a previous story, the booter service — lizardstresser[dot]su — is hosted at an Internet provider in Bosnia that is home to a large number of malicious and hostile sites.
That provider happens to be on the same “bulletproof” hosting network advertised by “sp3c1alist,” the administrator of the cybercrime forum Darkode. Until a few days ago, Darkode and LizardStresser shared the same Internet address. Interestingly, one of the core members of the Lizard Squad is an individual who goes by the nickname “Sp3c.”
On Jan. 4, KrebsOnSecurity discovered the location of the malware that powers the botnet. Hard-coded inside of that malware was the location of the LizardStresser botnet controller, which happens to be situated in the same small swath Internet address space occupied by the LizardStresser Web site (217.71.50.x)
The malicious code that converts vulnerable systems into stresser bots is a variation on a piece of rather crude malware first documented in November by Russian security firm Dr. Web, but the malware itself appears to date back to early 2014 (Google’s Chrome browser should auto-translate that page; for others, a Google-translated copy of the Dr. Web writeup is here).
As we can see in that writeup, in addition to turning the infected host into attack zombies, the malicious code uses the infected system to scan the Internet for additional devices that also allow access via factory default credentials, such as “admin/admin,” or “root/12345”. In this way, each infected host is constantly trying to spread the infection to new home routers and other devices accepting incoming connections (via telnet) with default credentials.
The botnet is not made entirely of home routers; some of the infected hosts appear to be commercial routers at universities and companies, and there are undoubtedly other devices involved. The preponderance of routers represented in the botnet probably has to do with the way that the botnet spreads and scans for new potential hosts. But there is no reason the malware couldn’t spread to a wide range of devices powered by the Linux operating system, including desktop servers and Internet-connected cameras. Continue reading →