7-Zip
7-Zip is a legitimate archive utility that threat actors have used during post-compromise collection and exfiltration. In the provided reporting, it was observed in UNC2447 intrusions as part of recon and exfiltration activity, and in a China-linked UAT-8837 campaign exploiting Sitecore CVE-2025-53690, where attackers compressed sensitive files prior to exfiltration. Specifically, the content states that files such as web.config and Windows registry hives were compressed with 7-Zip before being transferred to attacker-controlled infrastructure. The activity is mapped to MITRE ATT&CK T1560.001 (Archive via Utility). The content does not describe 7-Zip itself as malware, but as a dual-use utility leveraged by threat actors including UNC2447 and UAT-8837.
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Groups observed using it
1 distinct threat actor attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.
...UNC2447 has been observed using the following tools: ... 7ZIP.
Techniques & procedures
8 distinct techniques documented for this family, organized by ATT&CK tactic.
Stealth
2 techniquesCollection
5 techniquesMAZE Group 1 mapping includes “T1005: Data from Local System,” and narrative describes collecting directory listings and archiving data prior to exfiltration.
MAZE Group 2/3 mappings include “T1039: Data from Network Shared Drive,” and narrative describes archiving data from corporate file shares.
MAZE Group 2/3 mappings include “T1074: Data Staged,” and narrative describes archiving with 7zip (ad.7z) prior to exfiltration.
Archiving — compressing and encrypting the staged files into a single archive using tools like 7-Zip or PowerShell’s Compress-Archive.
Since ms.tmp is an archive, the threat actors would need to use the previously downloaded 7za.exe (7zip) to extract file contents via the password “123”.
Command and Control
1 technique7z.exe from AppData\Temp — not from Program Files (attacker-dropped tool) ... curl.exe from AppData\Temp — not a standard user workstation binary
Recent activity
3 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Legitimate compression utility abused to stage data for exfiltration (e.g., compressing web.config and registry hives such as SAM/SYSTEM).
Archiving utility used to compress/stage data prior to exfiltration.
The version that knows your environment.
Match every observed IP, domain, and hash against your live telemetry.
Named campaigns wielding this family, with evidence pinned to each claim.
CVEs this family uses for access and lateral movement.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Every documented technique, ranked by evidence weight.
Reddit, Mastodon, and CTI community discussion around this family.