The safest approach is to look for the file on a reputable modding forum or site with an active community. Search for "key root master mod version 1 3 6 apk download patched". When you find a potential download, check:

If you still intend to search for this file, here is how to identify a likely virus:

Downloading unverified rooting tools from unofficial repositories poses severe security risks to your personal data and your physical device. 1. Malware and Trojan Infections