One of the nastiest exploit kits on the web has gone silent, causing speculation its operators may have called it quits or arrested.
According to Symantec, the Angler exploit kit in May dominated web attacks among rival kits and was the most active of all throughout 2015. The for-hire attack kit, which is used to distribute ransomware and other malware, has a reputation for quickly integrating exploits for newly reported flaws, in particular for Adobe’s Flash Player browser plugin.
But as noted on Friday by malware researcher Kafeine, several online criminal gangs that have traditionally used Angler to infect computers and their malware all switched to alternative exploit kits. This transition happened within the space of a few days last week and the researcher said that by Tuesday, June 7, Angler had “totally vanished”.
Kafeine reported that the criminal groups had migrated chiefly to Neutrino and RIG, two other widely used exploit kits.
It’s not clear why Angler activity stalled last week or whether the ceasefire is permanent, but Kafeine speculated that it may be linked to the arrest of 50 Russian people who were accused of using the Lurk malware to steal the equivalent of $25m from Russian banks. Russia’s national security service, the FSB, announced the arrests on June 2.
While it would be significant if Angler had ceased operations, it changes little for end-user security and the threat of crypto ransomware.
Jérôme Segura, chief researcher at anti-malware firm Malwarebytes also reported a drop off in Angler attacks since June 6. One attacker, known as “SadClowns” who used Angler in malicious ads, had now switched to Neutrino.
F-Secure published a graph on Monday of exploit activity that demonstrates a significant reordering among for-hire attack kits that coincides with Angler’s demise. For now, it seems, Neutrino is the go-to replacement for Angler.
According to Symantec, in May Neutrino made up just 0.8 percent of all attacks that its software detected on end-user systems, compared to Angler, which made up 51 percent.
The new order has also been reflected in pricing. According to Kafeine, Neutrino’s operators jacked up prices and changed conditions on June 9. Formerly, Neutrino's exploits could be hired for $880 per week on a shared server and $3,500 per month on a dedicated server. The weekly rate has now vanished, while Neutrino’s dedicated server option has been doubled to $7,000 per month.
Kafeine speculates this may signal the Angler exploit kit out of action for the long term since rival gangs made similar price adjustments after the author of the Blackhole exploit kit was arrested in 2013.