Detection rules › Sigma

Greenbug Espionage Group Indicators

Status
test
Severity
critical
Log source
product windows, category process_creation
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects tools and process executions used by Greenbug in their May 2020 campaign as reported by Symantec

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Greenbug Espionage Group Indicators
id: 3711eee4-a808-4849-8a14-faf733da3612
status: test
description: Detects tools and process executions used by Greenbug in their May 2020 campaign as reported by Symantec
references:
    - https://symantec-enterprise-blogs.security.com/blogs/threat-intelligence/greenbug-espionage-telco-south-asia
author: Florian Roth (Nextron Systems)
date: 2020-05-20
modified: 2023-03-09
tags:
    - attack.stealth
    - attack.g0049
    - attack.execution
    - attack.t1059.001
    - attack.command-and-control
    - attack.t1105
    - attack.t1036.005
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        Image|endswith:
            - ':\ProgramData\adobe\Adobe.exe'
            - ':\ProgramData\oracle\local.exe'
            - '\revshell.exe'
            - '\infopagesbackup\ncat.exe'
            - ':\ProgramData\comms\comms.exe'
    selection_msf:
        CommandLine|contains|all:
            - '-ExecutionPolicy Bypass -File'
            - '\msf.ps1'
    selection_ncat:
        CommandLine|contains|all:
            - 'infopagesbackup'
            - '\ncat'
            - '-e cmd.exe'
    selection_powershell:
        CommandLine|contains:
            - 'system.Data.SqlClient.SqlDataAdapter($cmd); [void]$da.fill'
            - '-nop -w hidden -c $k=new-object'
            - '[Net.CredentialCache]::DefaultCredentials;IEX '
            - ' -nop -w hidden -c $m=new-object net.webclient;$m'
            - '-noninteractive -executionpolicy bypass whoami'
            - '-noninteractive -executionpolicy bypass netstat -a'
    selection_other:
        CommandLine|contains: 'L3NlcnZlcj1'  # base64 encoded '/server='
    condition: 1 of selection_*
falsepositives:
    - Unlikely
level: critical

Stages and Predicates

Stage 0: condition

1 of selection_*

Stage 1: selection_img

selection_img:
    Image|endswith:
        - ':\ProgramData\adobe\Adobe.exe'
        - ':\ProgramData\oracle\local.exe'
        - '\revshell.exe'
        - '\infopagesbackup\ncat.exe'
        - ':\ProgramData\comms\comms.exe'

Stage 2: selection_msf

selection_msf:
    CommandLine|contains|all:
        - '-ExecutionPolicy Bypass -File'
        - '\msf.ps1'

Stage 3: selection_ncat

selection_ncat:
    CommandLine|contains|all:
        - 'infopagesbackup'
        - '\ncat'
        - '-e cmd.exe'

Stage 4: selection_powershell

selection_powershell:
    CommandLine|contains:
        - 'system.Data.SqlClient.SqlDataAdapter($cmd); [void]$da.fill'
        - '-nop -w hidden -c $k=new-object'
        - '[Net.CredentialCache]::DefaultCredentials;IEX '
        - ' -nop -w hidden -c $m=new-object net.webclient;$m'
        - '-noninteractive -executionpolicy bypass whoami'
        - '-noninteractive -executionpolicy bypass netstat -a'

Stage 5: selection_other

selection_other:
    CommandLine|contains: 'L3NlcnZlcj1'

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.

FieldKindValues
CommandLinematch
  • -nop -w hidden -c $m=new-object net.webclient;$m
  • -ExecutionPolicy Bypass -File
  • -e cmd.exe
  • -noninteractive -executionpolicy bypass netstat -a
  • -noninteractive -executionpolicy bypass whoami
  • -nop -w hidden -c $k=new-object
  • L3NlcnZlcj1
  • [Net.CredentialCache]::DefaultCredentials;IEX
  • \msf.ps1
  • \ncat
  • infopagesbackup
  • system.Data.SqlClient.SqlDataAdapter($cmd); [void]$da.fill
Imageends_with
  • :\ProgramData\adobe\Adobe.exe
  • :\ProgramData\comms\comms.exe
  • :\ProgramData\oracle\local.exe
  • \infopagesbackup\ncat.exe
  • \revshell.exe