GuptiMiner: Hijacking Antivirus Updates for Distributing Backdoors and Casual Mining
We’ve been tracking a curious one here. Firstly, GuptiMiner is a highly sophisticated threat that uses an interesting infection chain along with a couple of techniques that include performing DNS requests to the attacker’s DNS servers, performing sideloading, extracting payloads from innocent-looking images, signing its payloads with a custom trusted root anchor certification authority, among others.
The main objective of GuptiMiner is to distribute backdoors within big corporate networks. We’ve encountered two different variants of these backdoors: The first is an enhanced build of PuTTY Link, providing SMB scanning of the local network and enabling lateral movement over the network to potentially vulnerable Windows 7 and Windows Server 2008 systems on the network. The second backdoor is multi-modular, accepting commands from the attacker to install more modules as well as focusing on scanning for stored private keys and cryptowallets on the local system.
Interestingly, GuptiMiner also distributes XMRig on the infected devices, which is a bit unexpected for such a thought-through operation.
