Windows: HackTool - SharpUp PrivEsc Tool Execution

Rule ID

PH_Rule_SIGMA_2341

Default Status

Enabled

Description

Detects the use of SharpUp, a tool for local privilege escalation. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_hktl_sharpup.yml

Severity

MITRE ATT&CK® Tactics

Defense Evasion

Defense Evasion consists of techniques that adversaries use to avoid detection throughout their compromise. Techniques used for defense evasion include uninstalling/disabling security software or obfuscating/encrypting data and scripts. Adversaries also leverage and abuse trusted processes to hide and masquerade their malware. Other tactics’ techniques are cross-listed here when those techniques include the added benefit of subverting defenses.

https://attack.mitre.org/tactics/TA0005

MITRE ATT&CK® Techniques

T1574.005

Hijack Execution Flow: Executable Installer File Permissions Weakness

Adversaries may execute their own malicious payloads by hijacking the binaries used by an installer. These processes may automatically execute specific binaries as part of their functionality or to perform other actions. If the permissions on the file system directory containing a target binary, or permissions on the binary itself, are improperly set, then the target binary may be overwritten with another binary using user-level permissions and executed by the original process. If the original process and thread are running under a higher permissions level, then the replaced binary will also execute under higher-level permissions, which could include SYSTEM.If the executing process is set to run at a specific time or during a certain event (e.g., system bootup) then this technique can also be used for persistence.

https://attack.mitre.org/techniques/T1574/005

Impacts

Server

Data Source

Windows Sysmon via FortiSIEM Agent

Detection

Correlation

Remediation Guidance

No remediation guidance specified

Time Window

If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.

300 seconds

Trigger Conditions

If the following defined pattern/s occur within a 300 second time window.

Filter

SubPattern Definitions

SubPattern Name: Filter

This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.

SubPattern Query

This is the query logic that matches incoming events

eventType="Win-Sysmon-1-Create-Process" AND (procName REGEXP "\\SharpUp\.exe$" OR description="SharpUp" OR command REGEXP ".*CachedGPPPassword.*|.*DomainGPPPassword.*|.*HijackablePaths.*|.*ModifiableScheduledTask.*|.*ModifiableServiceBinaries.*|.*ProcessDLLHijack.*|.*UnquotedServicePath.*")

Group by Attributes

This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID

command,description,hostName,procName

Aggregate Constraint

This is most typically a numerical constraint that defines when the rule should trigger an incident

COUNT(*) >= 1

Incident Attribute Mapping

This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.

The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern

command = Filter.command,
description = Filter.description,
hostName = Filter.hostName,
procName = Filter.procName

FortiSIEM Rules