If you encounter an archive that triggers this or similar errors, the CERT Coordination Center (CERT/CC) and other experts recommend:
: An archive is created with a header that falsely claims the content is uncompressed. B66zip
If you are not referring to the security vulnerability, "B66zip" might be a typo for: If you encounter an archive that triggers this
: If you receive an archive from an unknown source and your extraction software returns an "unsupported method" error, delete it immediately. : Ensure your security software is up to
: 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.
: Ensure your security software is up to date, as many vendors are currently implementing "aggressive" scanning modes to detect these mismatches. Alternative Meanings