Winrs Local Command Execution

Status: experimental
Severity: high
Log source: product windows, category process_creation
Author: Liran Ravich, Nasreddine Bencherchali
Source: github.com/SigmaHQ/sigma

Detects the execution of Winrs.exe where it is used to execute commands locally. Commands executed this way are launched under Winrshost.exe and can represent proxy execution used for defense evasion or lateral movement.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1218` System Binary Proxy Execution
Lateral Movement	`T1021.006` Remote Services: Windows Remote Management

Event coverage

Provider	Event	Title
Sysmon	Event ID 1	Process creation

Rule body yaml

title: Winrs Local Command Execution
id: bcfece3d-56fe-4545-9931-3b8e92927db1
status: experimental
description: |
    Detects the execution of Winrs.exe where it is used to execute commands locally.
    Commands executed this way are launched under Winrshost.exe and can represent proxy execution used for defense evasion or lateral movement.
references:
    - https://cardinalops.com/blog/living-off-winrm-abusing-complexity-in-remote-management/
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/winrs
author: Liran Ravich, Nasreddine Bencherchali
date: 2025-10-22
tags:
    - attack.lateral-movement
    - attack.stealth
    - attack.t1021.006
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        # Note: Example of command to simulate (winrm needs to be enabled): "c:\Windows\System32\winrs.exe" calc.exe
        - Image|endswith: '\winrs.exe'
        - OriginalFileName: 'winrs.exe'
    selection_local_ip:
        CommandLine|contains|windash:
            - '/r:localhost'
            - '/r:127.0.0.1'
            - '/r:[::1]'
            - '/remote:localhost'
            - '/remote:127.0.0.1'
            - '/remote:[::1]'
    filter_main_remote:
        CommandLine|contains|windash:
            - "/r:"
            - "/remote:"
    condition: all of selection_* or (selection_img and not 1 of filter_main_*)
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: `condition`

all of selection_* or (selection_img and not 1 of filter_main_*)

Stage 1: `selection_img`

selection_img:
    - Image|endswith: '\winrs.exe'
    - OriginalFileName: 'winrs.exe'

Stage 2: `selection_local_ip`

selection_local_ip:
    CommandLine|contains|windash:
        - '/r:localhost'
        - '/r:127.0.0.1'
        - '/r:[::1]'
        - '/remote:localhost'
        - '/remote:127.0.0.1'
        - '/remote:[::1]'

Stage 3: `selection_img`

selection_img:
    - Image|endswith: '\winrs.exe'
    - OriginalFileName: 'winrs.exe'

Stage 4: `not filter_main_remote`

filter_main_remote:
    CommandLine|contains|windash:
        - "/r:"
        - "/remote:"

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`CommandLine`	match	`/r:`
`CommandLine`	match	`/remote:`

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	`/r:127.0.0.1` transforms: `windash` `/r:[::1]` transforms: `windash` `/r:localhost` transforms: `windash` `/remote:127.0.0.1` transforms: `windash` `/remote:[::1]` transforms: `windash` `/remote:localhost` transforms: `windash`
`Image`	ends_with	`\winrs.exe` corpus 2 (sigma 2)
`OriginalFileName`	eq	`winrs.exe` corpus 2 (sigma 1, splunk 1)

`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)

Winrs Local Command Execution

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_local_ip`

Stage 3: `selection_img`

Stage 4: `not filter_main_remote`

Exclusions

Indicators

Keyboard shortcuts

Search operators

Winrs Local Command Execution

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_img

Stage 2: selection_local_ip

Stage 3: selection_img

Stage 4: not filter_main_remote

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_local_ip`

Stage 3: `selection_img`

Stage 4: `not filter_main_remote`