Pulsif.zip -

The file appears unreadable or corrupted to standard tools like Windows Explorer, 7-Zip, or WinRAR. However, attackers bundle a custom loader with the file that "resurrects" the malicious payload by correctly interpreting the malformed data.

Once extracted by the custom loader, the payload—which can include credential harvesters, ransomware, or webshells—executes on the victim's system. Why It’s Dangerous Pulsif.zip

Mitigate Pulse Connect Secure Product Vulnerabilities (Closed) The file appears unreadable or corrupted to standard

The core of the exploit lies in a manipulated file header. The attacker crafts the ZIP file to lie to security software, claiming the contents are uncompressed (STORED) when they are actually compressed using the DEFLATE method. When a security scanner reads the header, it attempts to scan the "uncompressed" data, but only sees what looks like random, harmless bytes. How the Attack Works Why It’s Dangerous Mitigate Pulse Connect Secure Product