Trojan.Keylogger.IStealer is a tool intended to help those in need of a keylogger. Trojan.istealer collects login credentials introduced into the computer even before the malicious Trojan invasions. The iStealer Trojan also features an extensive set of self-protection mechanisms, aimed at shielding it against dynamic and static analysis: anti-emulator routines, anti-process-monitoring, and the ability to run extremely silently when network monitoring applications are detected.”]
Source: https://www.bitdefender.com/blog/hotforsecurity/malware-review-trojan-keylogger-istealer/