Key Takeaways
What is AIRASHI?
AIRASHI is a variant of the AISURU botnet that has been active since at least late 2024. QiAnXin XLab reported on AIRASHI.
AISURU botnet is known for a large-scale DDoS attack that occurred in August 2024. The attack targeted distribution platforms of the Chinese game Black Myth: Wukong. Targets included Steam and Perfect World. The attack occurred in four waves, aligning with peak gaming hours, to be as disruptive as possible. Following this attack, AISURU ceased activity in September 2024. An updated and streamlined version, dubbed kitty, was released in October 2024. In late 2024, the threat actors behind AISURU released the current version of AIRASHI, a new AISURU variant.
AIRASHI uses a 0day vulnerability affecting cnPilot routers to spread itself. It also spreads via Nday vulnerabilities and weak Telnet passwords. Sample strings use RC4 encryption, and the C2 communication uses HMAC-SHA256 for verification and ChaCha20 for encryption. The names used for C2 domains (including xlabresearch, xlabsecurity, and foxthreatnointel) appear to be an attempt to mock security researchers. AIRASHI’s infrastructure uses at least 60 different IP addresses, hosted in multiple countries, which may make it more difficult to dismantle the botnet.
AIRASHI is capable of stable T-level DDoS attacks, with a tested attack capacity of 1-3 Tbps. AIRASHI, which has been observed spreading to hundreds of machines per day, does not appear to target a particular vertical. However, a large number of targets have been located in China, Poland, Russia, and the US. AIRASHI is updated often and appears to be under active development. Like AISURU, it has the capability to conduct large-scale DDoS attacks. For these reasons, PolySwarm analysts consider AIRASHI to be an emerging and evolving threat.
IOCs
PolySwarm has multiple samples of AIRASHI.
75a1199fbf8abd52bc957b07ff7574ddc98719272ad9f2f0d427178ac1c60967
ab67a6ae19b9d0fc79840894a257a2ece9110e13a027b7c19c8b3a99b88cdc49
371f9279bf5ef136fb6300eb0a26b38512a01b0b0d577954db67a823c789fa02
1576598bb6fa7163dd1d578639e6b1d0ef64ef82fbf5d2d34cfd22525187570c
You can use the following CLI command to search for all AIRASHI samples in our portal:
$ polyswarm link list -f AIRASHI
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