We discovered a new exploit kit we named Underminer that employs capabilities used by other exploit kits to deter researchers from tracking its activity or reverse engineering the payloads. Underminer delivers a bootkit that infects the system’s boot sectors as well as a cryptocurrency-mining malware named Hidden Mellifera. Underminer transfers malware via an encrypted transmission control protocol (TCP) tunnel and packages malicious files with a customized format similar to ROM file system format (romfs). These make the exploit kits and its payload challenging to analyze.Read More
The exploit kit landscape has been rocky since 2016, and we’ve observed several of the major players—Angler, Nuclear, Neutrino, Sundown—take a dip in operations or go private. New kits have popped up sporadically since then, sometimes revamped from old sources, but none have really gained traction. Despite that fact, cybercriminals continue to develop more of them.
We’ve uncovered a new exploit kit in the wild through a malvertising campaign we’ve dubbed “ProMediads”. We call this new exploit kit Sundown-Pirate, as it’s indeed a bootleg of its precursors and actually named so by its back panel.
ProMediads has been active as early as 2016, employing Rig and Sundown exploit kits to deliver malware. Its activities dropped off in mid-February this year, but suddenly welled on June 16 via Rig. However, we noticed that ProMediads eschewed Rig in favor of Sundown-Pirate on June 25.
It’s worth noting that Sundown-Pirate is only employed by ProMediads so far. This could mean that it’s yet another private exploit kit, like the similarly styled GreenFlash Sundown exploit kit that was exclusively used by the ShadowGate campaign.Read More
At the end of April this year, we found Astrum exploit kit employing Diffie-Hellman key exchange to prevent monitoring tools and researchers from replaying their traffic. As AdGholas started to push the exploit, we saw another evolution: Astrum using HTTPS to further obscure their malicious traffic. We spotted a new AdGholas malvertising campaign using the…Read More
The decline of exploit kit activity—particularly from well-known exploit kits like Magnitude, Nuclear, Neutrino, and Rig during the latter half of 2016—doesn’t mean exploit kits are throwing in the towel just yet. This is the case with Astrum (also known as Stagano), an old and seemingly reticent exploit kit we observed to have been updated multiple times as of late.
Astrum’s recent activities feature several upgrades and shows how it’s starting to move away from the more established malware mentioned above. It appears these changes were done to lay the groundwork for future campaigns, and possibly to broaden its use. With a modus operandi that deters analysis and forensics by abusing the Diffie-Hellman key exchange, it appears Astrum is throwing down the gauntlet.Read More