Pierluigi Paganini February 22, 2023

Researchers warn that the MyloBot botnet is rapidly spreading and it is infecting thousands of systems worldwide.

The MyloBot botnet has been active since 2017 and was first detailed by cybersecurity firm Deep Instinct in 2018. MyloBot is a highly evasive Windows botnet that supports advanced anti-analysis techniques.

The first sample of the bot analyzed by the experts (dated October 20, 2017) had three different stages.

Since November 2018, BitSight researchers started sinkholing the botnet. In 2018, the botnet’s proxy sample contained a lot of hardcoded DGA domains, allowing the researchers to track almost any bot. The researchers discovered that it reached a maximum of 250,000 unique daily infected machines at the beginning of 2020.

The latest version of the botnet, which appeared in early 2022, doesn’t contain hardcoded DGA domains, for this reason, the experts were not able to get a complete estimation of the number of infected systems.

Then the experts started monitoring Mylobot downloader’s domains to observe the botnet evolution. They also noticed a link between the Mylobot and the residential proxy service BHProxies, a circumstance that indicates that the compromised machines are being used by the latter.

Researchers warn that the botnet is rapidly growing, they observed it is infecting thousands of systems worldwide.

“We are currently seeing more than 50,000 unique infected systems every day, but we believe we are only seeing part of the full botnet, which may lead to more than 150,000 infected computers as advertised by BHProxies’ operators.” reads the report published by Bitsight.

Most of the infections were observed in India, followed by the US, Indonesia, and Iran.

Additional details, including indications of compromise (IoCs) are reported in the analysis published by the experts.

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Pierluigi Paganini

(SecurityAffairs – hacking, MyloBot botnet)