Archive Collected Data
Where this stands
One published detection covers this technique. Every one is unverified — no rule on Siemphony has been executed against real telemetry.
What the technique is
An adversary may compress and/or encrypt data that is collected prior to exfiltration. Compressing the data can help to obfuscate the collected data and minimize the amount of data sent over the network. Encryption can be used to hide information that is being exfiltrated from detection or make exfiltration less conspicuous upon inspection by a defender. Both compression and encryption are done prior to exfiltration, and can be performed using a utility, 3rd party library, or custom method.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN1458
Detects adversarial archiving of files prior to exfiltration by correlating execution of compression/encryption utilities (e.g., makecab.exe, rar.exe, 7z.exe, powershell Compress-Archive) with subsequent creation of large compressed or encrypted files. Identifies abnormal process lineage involving crypt32.dll usage, command-line arguments invoking compression switches, and file write operations to temporary or staging directories.
- AN1459
Detects adversarial archiving activity through invocation of utilities like tar, gzip, bzip2, or openssl used in non-administrative or unusual contexts. Correlates command execution patterns with file creation of compressed/encrypted outputs in staging directories (e.g., /tmp, /var/tmp).
- AN1460
Detects use of macOS-native archiving or encryption tools (zip, ditto, hdiutil) for staging collected data. Identifies unexpected invocation of archive utilities by Office apps, browsers, or background daemons. Correlates file creation of.zip/.dmg containers with process lineage anomalies.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.