Compress Data and Lock With Password for Exfiltration With 7-ZIP

Severity: medium
Author: frack113
Source: upstream

An adversary may compress or encrypt data that is collected prior to exfiltration using 3rd party utilities

MITRE ATT&CK coverage

Tactic	Techniques
Collection	`T1560.001` Archive Collected Data: Archive via Utility

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_img`

or:
Description|contains: 7-Zip
Image|endswith: '\7z.exe'
Image|endswith: '\7za.exe'
Image|endswith: '\7zr.exe'
OriginalFileName: 7z.exe
OriginalFileName: 7za.exe

Stage 2: `all of selection_password`

CommandLine|contains: ' -p'

Stage 3: `all of selection_action`

or:
CommandLine|contains: ' a '
CommandLine|contains: ' u '

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`CommandLine`	match	`-p` corpus 2 (sigma 2) `a` corpus 4 (sigma 4) `u`
`Description`	match	`7-Zip` corpus 2 (sigma 2)
`Image`	ends_with	`\7z.exe` corpus 3 (sigma 3) `\7za.exe` corpus 3 (sigma 3) `\7zr.exe` corpus 2 (sigma 2)
`OriginalFileName`	eq	`7z.exe` corpus 3 (sigma 3) `7za.exe` corpus 3 (sigma 3)