HackTool - SharpImpersonation Execution

Severity: high
Author: Sai Prashanth Pulisetti @pulisettis, Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects execution of the SharpImpersonation tool. Which can be used to manipulate tokens on a Windows computers remotely (PsExec/WmiExec) or interactively

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1134.001` Access Token Manipulation: Token Impersonation/Theft, `T1134.003` Access Token Manipulation: Make and Impersonate Token
Defense Evasion	`T1134.001` Access Token Manipulation: Token Impersonation/Theft, `T1134.003` Access Token Manipulation: Make and Impersonate Token

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `1 of selection_img`

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

Stage 2: `1 of selection_cli`

or:
CommandLine|contains: ' binary:'
CommandLine|contains: ' user:'
CommandLine|contains: ' shellcode:'
CommandLine|contains: ' user:'
CommandLine|contains: ' technique:CreateProcessAsUserW'
CommandLine|contains: ' technique:ImpersonateLoggedOnuser'

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	`binary:` `shellcode:` `technique:CreateProcessAsUserW` `technique:ImpersonateLoggedOnuser` `user:`
`Image`	ends_with	`\SharpImpersonation.exe` corpus 2 (sigma 2)
`OriginalFileName`	eq	`SharpImpersonation.exe`