Shell Process Spawned by Java.EXE

Severity: medium
Author: Andreas Hunkeler (@Karneades), Nasreddine Bencherchali
Source: upstream

Detects shell spawned from Java host process, which could be a sign of exploitation (e.g. log4j exploitation)

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation
Security-Auditing	4688	A new process has been created.

Stages and Predicates

Stage 1: `selection`

or:
Image|endswith: '\bash.exe'
Image|endswith: '\cmd.exe'
Image|endswith: '\powershell.exe'
Image|endswith: '\pwsh.exe'
ParentImage|endswith: '\java.exe'

Stage 2: `not 1 of filter_main_build`

CommandLine|contains: build
ParentImage|contains: build

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	`build`
`Image`	ends_with	`\bash.exe` corpus 17 (sigma 17) `\cmd.exe` corpus 92 (sigma 92) `\powershell.exe` corpus 143 (sigma 143) `\pwsh.exe` corpus 140 (sigma 140)
`ParentImage`	ends_with	`\java.exe` corpus 7 (sigma 7)
`ParentImage`	match	`build`