Hiding Files with Attrib.exe

Severity: medium
Author: Sami Ruohonen
Source: upstream

Detects usage of attrib.exe to hide files from users.

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1564.001` Hide Artifacts: Hidden Files and Directories

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_img`

or:
Image|endswith: '\attrib.exe'
OriginalFileName: ATTRIB.EXE

Stage 2: `all of selection_cli`

CommandLine|contains: ' +h '

Stage 3: `not 1 of filter_main_msiexec`

CommandLine|contains: '\desktop.ini '

Stage 4: `not 1 of filter_optional_intel`

CommandLine: '+R +H +S +A \\\*.cui'
ParentCommandLine: 'C:\\WINDOWS\\system32\\\*.bat'
ParentImage|endswith: '\cmd.exe'

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`	eq	`+R +H +S +A \\\*.cui`
`CommandLine`	match	`+h` `\desktop.ini`
`Image`	ends_with	`\attrib.exe` corpus 3 (sigma 3)
`OriginalFileName`	eq	`ATTRIB.EXE` corpus 2 (sigma 2)
`ParentCommandLine`	eq	`C:\\WINDOWS\\system32\\\*.bat`
`ParentImage`	ends_with	`\cmd.exe` corpus 13 (sigma 13)

Hiding Files with Attrib.exe

MITRE ATT&CK coverage

Event coverage

Stages and Predicates

Stage 1: all of selection_img

Stage 2: all of selection_cli

Stage 3: not 1 of filter_main_msiexec

Stage 4: not 1 of filter_optional_intel

Indicators

Stage 1: `all of selection_img`

Stage 2: `all of selection_cli`

Stage 3: `not 1 of filter_main_msiexec`

Stage 4: `not 1 of filter_optional_intel`