Is pkr a virus

Answer 1

The abbreviation "pkr" and other variations on it like "pk" are sometimes used as short for "packer", especially by antivirus software and companies. Packers are programs that compress programs to be smaller, basically speaking, and also can make them more difficult to detect. Few legitimate programs are packed, so some antivirus programs (like Sophos Anti-Virus) include a special detection for programs that have been packed or encrypted (Sophos detects them as Mal/EncPk). While this doesn't necessarily mean the program is a threat, you shouldn't open it unless you know what it is and trust its source.