Potential Manage-bde.wsf Abuse To Proxy Execution

Severity: high
Author: oscd.community, Natalia Shornikova, Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects potential abuse of the "manage-bde.wsf" script as a LOLBIN to proxy execution

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1216` System Script Proxy Execution

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_wscript_img`

or:
Image|endswith: '\wscript.exe'
OriginalFileName: wscript.exe

Stage 2: `all of selection_wscript_cli`

CommandLine|contains: manage-bde.wsf

Stage 3: `selection_parent`

or:
ParentImage|endswith: '\cscript.exe'
ParentImage|endswith: '\wscript.exe'
ParentCommandLine|contains: manage-bde.wsf

Stage 4: `not selection_filter_cmd`

Image|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`	match	`manage-bde.wsf`
`Image`	ends_with	`\cmd.exe` corpus 92 (sigma 92) `\wscript.exe` corpus 64 (sigma 64)
`OriginalFileName`	eq	`wscript.exe` corpus 15 (sigma 15)
`ParentCommandLine`	match	`manage-bde.wsf`
`ParentImage`	ends_with	`\cscript.exe` corpus 14 (sigma 14) `\wscript.exe` corpus 14 (sigma 14)

Potential Manage-bde.wsf Abuse To Proxy Execution

MITRE ATT&CK coverage

Event coverage

Stages and Predicates

Stage 1: all of selection_wscript_img

Stage 2: all of selection_wscript_cli

Stage 3: selection_parent

Stage 4: not selection_filter_cmd

Indicators

Stage 1: `all of selection_wscript_img`

Stage 2: `all of selection_wscript_cli`

Stage 3: `selection_parent`

Stage 4: `not selection_filter_cmd`