Nearly a month after it was discovered that the malware used WatchGuard firewall appliances as a stepping stone to obtaining remote access to infiltrated networks, ASUS routers have been the target of a budding botnet known as Cyclops Blink.
The botnet's primary objective is to develop an infrastructure for additional attacks on high-value targets, according to Trend Micro, given that none of the compromised hosts belongs to vital organisations or those that have an obvious value on economic, political, or military espionage.
Cyclops Blink has been identified by intelligence services in the United Kingdom and the United States as a replacement framework for VPNFilter, a malware that has targeted network equipment, especially small office/home office (SOHO) routers and network-attached storage (NAS) devices.
Sandworm (aka Voodoo Bear), a Russian state-sponsored actor has been linked to both VPNFilter and Cyclops Blink. It has also been tied to several high-profile cyberattacks, including the 2015 and 2016 attacks on the Ukrainian electrical grid, the 2017 NotPetya attack, and the 2018 Olympic Destroyer attack on the Winter Olympic Games.
The complex modular botnet, c language, affects a variety of ASUS router types, with the company admitting that it is working on a patch to handle any potential exploitation. –
- GT-AC5300 firmware under 3.0.0.4.386.xxxx
- GT-AC2900 firmware under 3.0.0.4.386.xxxx
- RT-AC5300 firmware under 3.0.0.4.386.xxxx
- RT-AC88U firmware under 3.0.0.4.386.xxxx
- RT-AC3100 firmware under 3.0.0.4.386.xxxx
- RT-AC86U firmware under 3.0.0.4.386.xxxx
- RT-AC68U, AC68R, AC68W, AC68P firmware under 3.0.0.4.386.xxxx
- RT-AC66U_B1 firmware under 3.0.0.4.386.xxxx
- RT-AC3200 firmware under 3.0.0.4.386.xxxx
- RT-AC2900 firmware under 3.0.0.4.386.xxxx
- RT-AC1900P, RT-AC1900P firmware under 3.0.0.4.386.xxxx
- RT-AC87U (end-of-life)
- RT-AC66U (end-of-life), and
- RT-AC56U (end-of-life)
Apart from employing OpenSSL to encrypt connections with its command-and-control (C2) servers, Cyclops Blink also includes specific modules that can read and write from the devices' flash memory, allowing it to persist and survive factory resets.
A second reconnaissance module acts as a medium for exfiltrating data from the hacked device to the C2 server, while a file download component is responsible for retrieving arbitrary payloads through HTTPS.
Although the exact form of initial access is unknown, Cyclops Blink has been affecting WatchGuard and Asus routers in the United States, India, Italy, Canada, and Russia since June 2019.
A law firm in Europe, a medium-sized entity producing medical equipment for dentists in Southern Europe, and a plumbing company in the United States are among the impacted hosts.
Because of the infrequency with which IoT devices and routers are patched and the lack of security software, Trend Micro has warned that this might lead to the establishment of "eternal botnets."
The researchers stated, "Once an IoT device is infected with malware, an attacker can have unrestricted internet access for downloading and deploying more stages of malware for reconnaissance, espionage, proxying, or anything else that the attacker wants to do. In the case of Cyclops Blink, we have seen devices that were compromised for over 30 months (about two and a half years) in a row and were being set up as stable command-and-control servers for other bots."
