TrojanDownloader:MSIL/AsyncRAT is a downloader variant written in Microsoft Intermediate Language (MSIL) that facilitates the distribution of AsyncRAT. It is commonly propagated through phishing attacks, embedded links in cloud-hosted services, and malicious email attachments. AsyncRAT is a remote access trojan (RAT) that is similar to RevengeRAT (also known as Revenge). RevengeRAT, is a malware known to infect devices through malicious email attachments or malicious ads on compromised websites. Attackers use spear-phishing to deliver the malware as a Visual Basic (VB) script, contained in either .zip or .rar archives, or in .doc files. They also use emails or images embedded with links that redirect users to cloud-hosting sites, such as GoogleDrive, OneDrive, iCloud drive, which host the malware.

Read the following blogs for details:

• From Visual Basic Script to Revenge RAT
• RATs in the Library
• RevengeRAT Distributed via Bit.ly, BlogSpot, and Pastebin C2 Infrastructure