Suspicious WMIC Execution Via Office Process

Severity: high
Author: Vadim Khrykov, Cyb3rEng
Source: upstream

Office application called wmic to proxye execution through a LOLBIN process. This is often used to break suspicious parent-child chain (Office app spawns LOLBin).

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1047` Windows Management Instrumentation, `T1204.002` User Execution: Malicious File
Defense Evasion	`T1218.010` System Binary Proxy Execution: Regsvr32

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_parent`

or:
ParentImage|endswith: '\EQNEDT32.EXE'
ParentImage|endswith: '\EXCEL.EXE'
ParentImage|endswith: '\MSACCESS.EXE'
ParentImage|endswith: '\MSPUB.exe'
ParentImage|endswith: '\ONENOTE.EXE'
ParentImage|endswith: '\POWERPNT.exe'
ParentImage|endswith: '\VISIO.exe'
ParentImage|endswith: '\WINWORD.EXE'
ParentImage|endswith: '\wordpad.exe'
ParentImage|endswith: '\wordview.exe'

Stage 2: `all of selection_wmic_img`

or:
Image|endswith: '\wbem\WMIC.exe'
OriginalFileName: wmic.exe

Stage 3: `all of selection_wmic_cli`

or:
CommandLine|contains: cscript
CommandLine|contains: mshta
CommandLine|contains: msiexec
CommandLine|contains: regsvr32
CommandLine|contains: rundll32
CommandLine|contains: verclsid
CommandLine|contains: wscript
CommandLine|contains: call
CommandLine|contains: create
CommandLine|contains: process

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	`call` corpus 7 (sigma 7) `create` corpus 8 (sigma 8) `cscript` corpus 12 (sigma 12) `mshta` corpus 11 (sigma 11) `msiexec` corpus 4 (sigma 4) `process` corpus 3 (sigma 3) `regsvr32` corpus 11 (sigma 11) `rundll32` corpus 19 (sigma 19) `verclsid` `wscript` corpus 12 (sigma 12)
`Image`	ends_with	`\wbem\WMIC.exe`
`OriginalFileName`	eq	`wmic.exe` corpus 33 (sigma 33)
`ParentImage`	ends_with	`\EQNEDT32.EXE` corpus 2 (sigma 2) `\EXCEL.EXE` corpus 3 (sigma 3) `\MSACCESS.EXE` corpus 2 (sigma 2) `\MSPUB.exe` corpus 3 (sigma 3) `\ONENOTE.EXE` corpus 2 (sigma 2) `\POWERPNT.exe` corpus 3 (sigma 3) `\VISIO.exe` corpus 3 (sigma 3) `\WINWORD.EXE` corpus 3 (sigma 3) `\wordpad.exe` corpus 2 (sigma 2) `\wordview.exe` corpus 2 (sigma 2)