From 2-spyware.com
Backdoor:MSIL/AsyncRAT is Microsoft’s detection name for a Remote Access Trojan known as AsyncRAT. This malware belongs to a category of programs that initially can be used for surveillance or educational purposes – This particular RAT is available as an open-source project for Windows. However, many malicious actors or cybercriminal groups employ these tools for nefarious purposes and inject them into companies’ or users’ computers, as well as networks, illegally. As a result, they serve as malware that opens a backdoor on a compromised system, allowing the attackers to perform all types of malicious actions.