April_10-04-2022.7z

: Used "thread hijacking" (replying to old email chains). File Name : Followed the pattern [Month]_[Date]-[Year].7z . Lure : Contained a malicious .lnk or .vbs file inside. 📝 Recommended Blog Coverage

: They explain why the hackers used the .7z format (it has a higher compression ratio and was less scrutinized by legacy scanners). 💡 Why this file is "Interesting"

: The password was usually provided in the email body, making the user feel "secure" while actually helping the malware bypass the gateway.

The SANS "Handler's Diary" provided real-time analysis in April 2022. They detailed how attackers switched to .7z files to bypass email filters that were previously blocking .zip files. 2. Brad Duncan's Malware-Traffic-Analysis This is the "gold standard" for this specific file. : PCAP files and malware samples. Link : Malware-Traffic-Analysis.net

The most detailed technical breakdown of this specific file naming convention and campaign can be found on these cybersecurity blogs: 1. SANS Internet Storm Center (ISC)

Both firms published blogs in early 2022 regarding the resurgence of . Unit 42 : Look for their research on Emotet's evolution .

: It marked a shift where attackers used password-protected archives to hide the payload from automated sandbox analysis.

: It provides the exact infection chain, showing how the .7z file leads to a DLL execution via regsvr32.exe . 3. Trend Micro / Palo Alto Unit 42

• APRIL_10-04-2022.7z