Distributing malware inside password-protected archives has long been one of the main techniques used by attackers to bypass email security filters. More recently, researchers have spotted a variation that uses nested self-extracting archives that no longer require victims to input the password.
“This is significant because one of the most difficult obstacles threat actors face when conducting this type of spam campaign is to convince the target to open the archive using the provided password,” researchers from Trustwave SpiderLabs said in a new report.
