CobaltStrike Named Pipe

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

Detects the creation of a named pipe as used by CobaltStrike

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1055` Process Injection
Stealth	`T1055` Process Injection

Event coverage

Provider	Event	Title
Sysmon	Event ID 17	PipeEvent (Pipe Created)
Sysmon	Event ID 18	PipeEvent (Pipe Connected)

Rule body yaml

title: CobaltStrike Named Pipe
id: d5601f8c-b26f-4ab0-9035-69e11a8d4ad2
related:
    - id: 85adeb13-4fc9-4e68-8a4a-c7cb2c336eb7 # Patterns
      type: similar
    - id: 0e7163d4-9e19-4fa7-9be6-000c61aad77a # Regex
      type: similar
status: test
description: Detects the creation of a named pipe as used by CobaltStrike
references:
    - https://twitter.com/d4rksystem/status/1357010969264873472
    - https://labs.f-secure.com/blog/detecting-cobalt-strike-default-modules-via-named-pipe-analysis/
    - https://github.com/SigmaHQ/sigma/issues/253
    - https://blog.cobaltstrike.com/2021/02/09/learn-pipe-fitting-for-all-of-your-offense-projects/
    - https://redcanary.com/threat-detection-report/threats/cobalt-strike/
author: Florian Roth (Nextron Systems), Wojciech Lesicki
date: 2021-05-25
modified: 2022-10-31
tags:
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1055
logsource:
    product: windows
    category: pipe_created
    definition: 'Note that you have to configure logging for Named Pipe Events in Sysmon config (Event ID 17 and Event ID 18). The basic configuration is in popular sysmon configuration (https://github.com/SwiftOnSecurity/sysmon-config), but it is worth verifying. You can also use other repo, e.g. https://github.com/Neo23x0/sysmon-config, https://github.com/olafhartong/sysmon-modular. How to test detection? You can always use Cobalt Strike, but also you can check powershell script from this site https://svch0st.medium.com/guide-to-named-pipes-and-hunting-for-cobalt-strike-pipes-dc46b2c5f575'
detection:
    selection_MSSE:
        PipeName|contains|all:
            - '\MSSE-'
            - '-server'
    selection_postex:
        PipeName|startswith: '\postex_' # Also include the pipe "\postex_ssh_"
    selection_status:
        PipeName|startswith: '\status_'
    selection_msagent:
        PipeName|startswith: '\msagent_'
    selection_mojo:
        PipeName|startswith: '\mojo_'
    selection_interprocess:
        PipeName|startswith: '\interprocess_'
    selection_samr:
        PipeName|startswith: '\samr_'
    selection_netlogon:
        PipeName|startswith: '\netlogon_'
    selection_srvsvc:
        PipeName|startswith: '\srvsvc_'
    selection_lsarpc:
        PipeName|startswith: '\lsarpc_'
    selection_wkssvc:
        PipeName|startswith: '\wkssvc_'
    condition: 1 of selection*
falsepositives:
    - Unknown
level: critical

Stages and Predicates

Stage 0: `condition`

1 of selection*

Stage 1: `selection_MSSE`

selection_MSSE:
    PipeName|contains|all:
        - '\MSSE-'
        - '-server'

Stage 2: `selection_postex`

selection_postex:
    PipeName|startswith: '\postex_'

Stage 3: `selection_status`

selection_status:
    PipeName|startswith: '\status_'

Stage 4: `selection_msagent`

selection_msagent:
    PipeName|startswith: '\msagent_'

Stage 5: `selection_mojo`

selection_mojo:
    PipeName|startswith: '\mojo_'

Stage 6: `selection_interprocess`

selection_interprocess:
    PipeName|startswith: '\interprocess_'

Stage 7: `selection_samr`

selection_samr:
    PipeName|startswith: '\samr_'

Stage 8: `selection_netlogon`

selection_netlogon:
    PipeName|startswith: '\netlogon_'

Stage 9: `selection_srvsvc`

selection_srvsvc:
    PipeName|startswith: '\srvsvc_'

Stage 10: `selection_lsarpc`

selection_lsarpc:
    PipeName|startswith: '\lsarpc_'

Stage 11: `selection_wkssvc`

selection_wkssvc:
    PipeName|startswith: '\wkssvc_'

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
`PipeName`	match	`-server` `\MSSE-`
`PipeName`	starts_with	`\interprocess_` `\lsarpc_` `\mojo_` `\msagent_` `\netlogon_` `\postex_` `\samr_` `\srvsvc_` `\status_` `\wkssvc_`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

CobaltStrike Named Pipe

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_MSSE`

Stage 2: `selection_postex`

Stage 3: `selection_status`

Stage 4: `selection_msagent`

Stage 5: `selection_mojo`

Stage 6: `selection_interprocess`

Stage 7: `selection_samr`

Stage 8: `selection_netlogon`

Stage 9: `selection_srvsvc`

Stage 10: `selection_lsarpc`

Stage 11: `selection_wkssvc`

Indicators

Keyboard shortcuts

Search operators

CobaltStrike Named Pipe

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_MSSE

Stage 2: selection_postex

Stage 3: selection_status

Stage 4: selection_msagent

Stage 5: selection_mojo

Stage 6: selection_interprocess

Stage 7: selection_samr

Stage 8: selection_netlogon

Stage 9: selection_srvsvc

Stage 10: selection_lsarpc

Stage 11: selection_wkssvc

Indicators

Stage 0: `condition`

Stage 1: `selection_MSSE`

Stage 2: `selection_postex`

Stage 3: `selection_status`

Stage 4: `selection_msagent`

Stage 5: `selection_mojo`

Stage 6: `selection_interprocess`

Stage 7: `selection_samr`

Stage 8: `selection_netlogon`

Stage 9: `selection_srvsvc`

Stage 10: `selection_lsarpc`

Stage 11: `selection_wkssvc`