Zombie ZIP is a technique used by attackers to hide malware within ZIP archives. It exploits a discrepancy between how different programs read the ZIP file format.
: Ensure your security software is up to date, as many vendors are currently implementing "aggressive" scanning modes to detect these mismatches. Alternative Meanings B66zip
If you encounter an archive that triggers this or similar errors, the CERT Coordination Center (CERT/CC) and other experts recommend: Zombie ZIP is a technique used by attackers
If you are not referring to the security vulnerability, "B66zip" might be a typo for: B66zip
: Because the data looks like random, uncompressed bytes, most antivirus scanners (over 95% at the time of discovery) fail to recognize known malware signatures within it.