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Detection rules › Sigma

Lace Tempest Cobalt Strike Download

Status
test
Severity
high
Log source
category process_creation, product windows
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects specific command line execution used by Lace Tempest to download Cobalt Strike as reported by SysAid Team

Known false positives

  • Unlikely

MITRE ATT&CK coverage

TacticTechniques
ExecutionNo specific technique

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 1: Process creation
Security-AuditingEvent ID 4688: A new process has been created.

Rule body

title: Lace Tempest Cobalt Strike Download
id: aa5b0a40-ed88-46aa-9fdc-0337b379ca9d
status: test
description: Detects specific command line execution used by Lace Tempest to download Cobalt Strike as reported by SysAid Team
references:
    - https://www.sysaid.com/blog/service-desk/on-premise-software-security-vulnerability-notification
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-11-09
tags:
    - attack.execution
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains|all:
            - -nop -w hidden -c IEX ((new-object net.webclient).downloadstring(
            - /a')
    condition: selection
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    CommandLine|contains|all:
        - -nop -w hidden -c IEX ((new-object net.webclient).downloadstring(
        - /a')

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • -nop -w hidden -c IEX ((new-object net.webclient).downloadstring(
  • /a')
field:"CommandLine" kind:match