Emotet is a notorious email-based malware behind several botnet-driven spam campaigns and ransomware attacks. Researchers discovered a flaw that allowed researchers to activate a kill-switch to stop the malware from infecting systems for six months. The malware authors patched their malware and closed the vulnerability, but EmoCrash was still active at the start of their full return, up until August 6, 2020, for 182 days, before the malware authors patched their malware. The fix was released in mid-April, but it wasn’t until an update to the malware loader removed the vulnerable registry value code.
Source: https://thehackernews.com/2020/08/emotet-botnet-malware.html