Remote Access Tool - AnyDesk Execution With Known Revoked Signing Certificate

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

Detects the execution of an AnyDesk binary with a version prior to 8.0.8. Prior to version 8.0.8, the Anydesk application used a signing certificate that got compromised by threat actors. Use this rule to detect instances of older versions of Anydesk using the compromised certificate This is recommended in order to avoid attackers leveraging the certificate and signing their binaries to bypass detections.

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	No specific technique
Execution	No specific technique

Event coverage

Provider	Event	Title
Sysmon	Event ID 1	Process creation

Rule body yaml

title: Remote Access Tool - AnyDesk Execution With Known Revoked Signing Certificate
id: 41f407b5-3096-44ea-a74f-96d04fbc41be
status: test
description: |
    Detects the execution of an AnyDesk binary with a version prior to 8.0.8.
    Prior to version 8.0.8, the Anydesk application used a signing certificate that got compromised by threat actors.
    Use this rule to detect instances of older versions of Anydesk using the compromised certificate
    This is recommended in order to avoid attackers leveraging the certificate and signing their binaries to bypass detections.
references:
    - https://www.bleepingcomputer.com/news/security/anydesk-says-hackers-breached-its-production-servers-reset-passwords/
    - https://anydesk.com/en/changelog/windows
author: Sai Prashanth Pulisetti, Nasreddine Bencherchali (Nextron Systems)
date: 2024-02-08
tags:
    - attack.execution
    - attack.initial-access
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        - Image|endswith: '\AnyDesk.exe'
        - Description: 'AnyDesk'
        - Product: 'AnyDesk'
        - Company: 'AnyDesk Software GmbH'
    selection_version:
        FileVersion|startswith:
            - '7.0.'
            - '7.1.'
            - '8.0.1'
            - '8.0.2'
            - '8.0.3'
            - '8.0.4'
            - '8.0.5'
            - '8.0.6'
            - '8.0.7'
    filter_main_uninstall:
        CommandLine|contains:
            - ' --remove'
            - ' --uninstall'
    condition: all of selection_* and not 1 of filter_main_*
falsepositives:
    - Unlikely
level: medium

Stages and Predicates

Stage 0: `condition`

all of selection_* and not 1 of filter_main_*

Stage 1: `selection_img`

selection_img:
    - Image|endswith: '\AnyDesk.exe'
    - Description: 'AnyDesk'
    - Product: 'AnyDesk'
    - Company: 'AnyDesk Software GmbH'

Stage 2: `selection_version`

selection_version:
    FileVersion|startswith:
        - '7.0.'
        - '7.1.'
        - '8.0.1'
        - '8.0.2'
        - '8.0.3'
        - '8.0.4'
        - '8.0.5'
        - '8.0.6'
        - '8.0.7'

Stage 3: `not filter_main_uninstall`

filter_main_uninstall:
    CommandLine|contains:
        - ' --remove'
        - ' --uninstall'

Exclusions

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

Field	Kind	Excluded values
`CommandLine`	match	`--remove`
`CommandLine`	match	`--uninstall`

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
`Company`	eq	`AnyDesk Software GmbH` corpus 3 (sigma 3)
`Description`	eq	`AnyDesk` corpus 3 (sigma 3)
`FileVersion`	starts_with	`7.0.` `7.1.` `8.0.1` `8.0.2` `8.0.3` `8.0.4` `8.0.5` `8.0.6` `8.0.7`
`Image`	ends_with	`\AnyDesk.exe` corpus 5 (sigma 5)
`Product`	eq	`AnyDesk` corpus 3 (sigma 3)

`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)

Remote Access Tool - AnyDesk Execution With Known Revoked Signing Certificate

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_version`

Stage 3: `not filter_main_uninstall`

Exclusions

Indicators

Keyboard shortcuts

Search operators

Remote Access Tool - AnyDesk Execution With Known Revoked Signing Certificate

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_img

Stage 2: selection_version

Stage 3: not filter_main_uninstall

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_version`

Stage 3: `not filter_main_uninstall`