Tracking down the Ron Paul spam botnet
Six weeks ago, a small blizzard of spam promoting Ron Paul, the Republican underdog running for US president, touched off a lot of head scratching. Had politics finally stooped to a place where candidates would resort to such a reviled means of communication?
Or worse, were the missives the beginning of a new type of smear campaign in which opponents unleashed torrents of emails in an attempt to tarnish the standing of their rivals?
Joe Stewart, a cyber-gumshoe at SecureWorks, can't give definitive answers to those questions, but he's unearthed some interesting evidence that gives a rare, behind-the-scenes glimpse into a state-of-the-art botnet spam system. More specifically, he's uncovered new information about "Reactor Mailer," the sophisticated piece of spamware used by Ukrainians to send the Ron Paul messages to more than 162 million addresses.
Now in its third version, Reactor is piece of software written in the Python language that runs on a botnet's command and control server. It operates off the software-as-a-service model made popular by legitimate companies such as Salesforce.com and offers some powerful features. To whit, it comes integrated with SpamAssassin, to make it easier for spammers to evade filters.
It is also based on templates that work seamlessly with botnets created by the Trojan.Srizbi. This gave the spam engine spewing out the Ron Paul emails the capacity to send more than 200 million emails in a single day, far more than would be possible through more traditional proxy-based methods of sending spam.
"It's pretty good programming," said Stewart, whose formal title at Atlanta-based SecureWorks is senior researcher. "The person that's at the core of this has done a pretty thorough job."
Stewart managed to obtain a copy of Reactor through the help of Spamhaus, the network of antispam volunteers. He began by tracking IP addresses that sent the Ron Paul emails, and in time discovered the US-based server used to control the 3,000-strong network. (Stewart also said he received invaluable assistance from colleagues at myNetWatchman and IronPort.
When Stewart logged into Reactor, he found a list of saved tasks that included one titled RonP_3 belonging to a spammer calling himself nenastnyj. The console had about 3,000 zombies under its command and included a 3.4GB file containing more than 162 million addresses and a feedback mechanism so the spammer would know when emails were rejected.
Stewart's conclusion: The Ron Paul incident was very much a "one-off job among the other tasks" saved on the spam console. We still don't know who directed the emails to be sent or what the motivation was, but thanks to Stewart, we now know they were sent by the same people who populate our inboxes with penis improvement campaigns on a daily basis. ®