Cybercriminals are increasingly turning to a legitimate, Pastebin-like web service for downloading malware — such as AgentTesla and LimeRAT — in spear-phishing attacks.
Pastebin, a code-hosting service that enables users to share plain text through public posts called “pastes,” currently has 17 million unique monthly users and is popular among cybercriminals (such as the FIN5 APT group and Rocke threat group) for hosting their payloads or command-and-control (C2) infrastructure. But now, more malware and ransomware families are starting to utilize another service, with the domain Paste.nrecom[.]net.
This service been around since May 2014, and has a similar function as Pastebin. It also has an API (powered by open-source PHP based pastebin Stikked) that allows for scripting. Researchers with Juniper Networks said that the API feature is lucrative for cybercriminals, who can leverage it to easily insert and update their data programmatically.
“Although using legitimate web services is not novel, this is the first time that we have seen threat actors use paste.nrecom[.]net,” said Paul Kimayong, researcher with Juniper Networks, in a Monday analysis. “Among the malware we have identified are AgentTesla, LimeRAT, [W3Cryptolocker] Ransomware and Redline Stealer.”