COM Object Hijacking Via Modification Of Default System CLSID Default Value

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

Detects potential COM object hijacking via modification of default system CLSID.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1546.015` Event Triggered Execution: Component Object Model Hijacking
Privilege Escalation	`T1546.015` Event Triggered Execution: Component Object Model Hijacking

Event coverage

Provider	Event	Title
Sysmon	Event ID 13	RegistryEvent (Value Set)

Rule body yaml

title: COM Object Hijacking Via Modification Of Default System CLSID Default Value
id: 790317c0-0a36-4a6a-a105-6e576bf99a14
related:
    - id: 3d968d17-ffa4-4bc0-bfdc-f139de76ce77
      type: obsolete
    - id: a0ff33d8-79e4-4cef-b4f3-9dc4133ccd12
      type: obsolete
status: experimental
description: Detects potential COM object hijacking via modification of default system CLSID.
references:
    - https://www.microsoft.com/security/blog/2022/07/27/untangling-knotweed-european-private-sector-offensive-actor-using-0-day-exploits/ (idea)
    - https://unit42.paloaltonetworks.com/snipbot-romcom-malware-variant/
    - https://blog.talosintelligence.com/uat-5647-romcom/
    - https://global.ptsecurity.com/analytics/pt-esc-threat-intelligence/darkhotel-a-cluster-of-groups-united-by-common-techniques
    - https://threatbook.io/blog/Analysis-of-APT-C-60-Attack-on-South-Korea
    - https://catalyst.prodaft.com/public/report/inside-the-latest-espionage-campaign-of-nebulous-mantis
    - https://github.com/rtecCyberSec/BitlockMove
    - https://cert.gov.ua/article/6284080
    - https://securelist.com/forumtroll-apt-hacking-team-dante-spyware/117851/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2024-07-16
modified: 2025-11-10
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.015
logsource:
    category: registry_set
    product: windows
detection:
    selection_target_root:
        TargetObject|contains: '\CLSID\'
        TargetObject|endswith:
            - '\InprocServer32\(Default)'
            - '\LocalServer32\(Default)'
    selection_target_builtin_clsid:
        TargetObject|contains:
            # Note: Add other legitimate CLSID
            - '\{1f486a52-3cb1-48fd-8f50-b8dc300d9f9d}\'
            - '\{2155fee3-2419-4373-b102-6843707eb41f}\'
            - '\{4590f811-1d3a-11d0-891f-00aa004b2e24}\'
            - '\{4de225bf-cf59-4cfc-85f7-68b90f185355}\'
            - '\{ddc05a5a-351a-4e06-8eaf-54ec1bc2dcea}\'
            - '\{F56F6FDD-AA9D-4618-A949-C1B91AF43B1A}\'
            - '\{F82B4EF1-93A9-4DDE-8015-F7950A1A6E31}\'
            - '\{7849596a-48ea-486e-8937-a2a3009f31a9}\'
            - '\{0b91a74b-ad7c-4a9d-b563-29eef9167172}\'
            - '\{603D3801-BD81-11d0-A3A5-00C04FD706EC}\'
            - '\{30D49246-D217-465F-B00B-AC9DDD652EB7}\'
            - '\{A7A63E5C-3877-4840-8727-C1EA9D7A4D50}\'
            - '\{2227A280-3AEA-1069-A2DE-08002B30309D}\'
            - '\{2DEA658F-54C1-4227-AF9B-260AB5FC3543}\'
            - '\{AA509086-5Ca9-4C25-8F95-589D3C07B48A}\'
    selection_susp_location_1:
        Details|contains:
            # Note: Add more suspicious paths and locations
            - ':\Perflogs\'
            - '\AppData\Local\'
            - '\Desktop\'
            - '\Downloads\'
            - '\Microsoft\Windows\Start Menu\Programs\Startup\'
            - '\System32\spool\drivers\color\' # as seen in the knotweed blog
            - '\Temporary Internet'
            - '\Users\Public\'
            - '\Windows\Temp\'
            - '%appdata%'
            - '%temp%'
            - '%tmp%'
    selection_susp_location_2:
        - Details|contains|all:
              - ':\Users\'
              - '\Favorites\'
        - Details|contains|all:
              - ':\Users\'
              - '\Favourites\'
        - Details|contains|all:
              - ':\Users\'
              - '\Contacts\'
        - Details|contains|all:
              - ':\Users\'
              - '\Pictures\'
    condition: all of selection_target_* and 1 of selection_susp_location_*
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: `condition`

all of selection_target_* and 1 of selection_susp_location_*

Stage 1: `selection_target_root`

selection_target_root:
    TargetObject|contains: '\CLSID\'
    TargetObject|endswith:
        - '\InprocServer32\(Default)'
        - '\LocalServer32\(Default)'

Stage 2: `selection_target_builtin_clsid`

selection_target_builtin_clsid:
    TargetObject|contains:
        - '\{1f486a52-3cb1-48fd-8f50-b8dc300d9f9d}\'
        - '\{2155fee3-2419-4373-b102-6843707eb41f}\'
        - '\{4590f811-1d3a-11d0-891f-00aa004b2e24}\'
        - '\{4de225bf-cf59-4cfc-85f7-68b90f185355}\'
        - '\{ddc05a5a-351a-4e06-8eaf-54ec1bc2dcea}\'
        - '\{F56F6FDD-AA9D-4618-A949-C1B91AF43B1A}\'
        - '\{F82B4EF1-93A9-4DDE-8015-F7950A1A6E31}\'
        - '\{7849596a-48ea-486e-8937-a2a3009f31a9}\'
        - '\{0b91a74b-ad7c-4a9d-b563-29eef9167172}\'
        - '\{603D3801-BD81-11d0-A3A5-00C04FD706EC}\'
        - '\{30D49246-D217-465F-B00B-AC9DDD652EB7}\'
        - '\{A7A63E5C-3877-4840-8727-C1EA9D7A4D50}\'
        - '\{2227A280-3AEA-1069-A2DE-08002B30309D}\'
        - '\{2DEA658F-54C1-4227-AF9B-260AB5FC3543}\'
        - '\{AA509086-5Ca9-4C25-8F95-589D3C07B48A}\'

Stage 3: `selection_susp_location_1`

selection_susp_location_1:
    Details|contains:
        - ':\Perflogs\'
        - '\AppData\Local\'
        - '\Desktop\'
        - '\Downloads\'
        - '\Microsoft\Windows\Start Menu\Programs\Startup\'
        - '\System32\spool\drivers\color\'
        - '\Temporary Internet'
        - '\Users\Public\'
        - '\Windows\Temp\'
        - '%appdata%'
        - '%temp%'
        - '%tmp%'

Stage 4: `selection_susp_location_2`

selection_susp_location_2:
    - Details|contains|all:
          - ':\Users\'
          - '\Favorites\'
    - Details|contains|all:
          - ':\Users\'
          - '\Favourites\'
    - Details|contains|all:
          - ':\Users\'
          - '\Contacts\'
    - Details|contains|all:
          - ':\Users\'
          - '\Pictures\'

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
`Details`	match	`%appdata%` corpus 4 (sigma 3, chronicle 1) `%temp%` corpus 5 (sigma 4, chronicle 1) `%tmp%` corpus 5 (sigma 4, chronicle 1) `:\Perflogs\` corpus 4 (sigma 4) `:\Users\` corpus 4 (sigma 4) `\AppData\Local\` corpus 2 (sigma 2) `\Contacts\` corpus 4 (sigma 4) `\Desktop\` corpus 3 (sigma 3) `\Downloads\` corpus 2 (sigma 2) `\Favorites\` corpus 3 (sigma 3) `\Favourites\` corpus 3 (sigma 3) `\Microsoft\Windows\Start Menu\Programs\Startup\` corpus 2 (sigma 2) `\Pictures\` corpus 3 (sigma 3) `\System32\spool\drivers\color\` `\Temporary Internet` corpus 3 (sigma 3) `\Users\Public\` corpus 5 (sigma 5) `\Windows\Temp\` corpus 5 (sigma 5)
`TargetObject`	ends_with	`\InprocServer32\(Default)` `\LocalServer32\(Default)`
`TargetObject`	match	`\CLSID\` `\{0b91a74b-ad7c-4a9d-b563-29eef9167172}\` `\{1f486a52-3cb1-48fd-8f50-b8dc300d9f9d}\` `\{2155fee3-2419-4373-b102-6843707eb41f}\` `\{2227A280-3AEA-1069-A2DE-08002B30309D}\` `\{2DEA658F-54C1-4227-AF9B-260AB5FC3543}\` `\{30D49246-D217-465F-B00B-AC9DDD652EB7}\` `\{4590f811-1d3a-11d0-891f-00aa004b2e24}\` `\{4de225bf-cf59-4cfc-85f7-68b90f185355}\` `\{603D3801-BD81-11d0-A3A5-00C04FD706EC}\` `\{7849596a-48ea-486e-8937-a2a3009f31a9}\` `\{A7A63E5C-3877-4840-8727-C1EA9D7A4D50}\` `\{AA509086-5Ca9-4C25-8F95-589D3C07B48A}\` `\{F56F6FDD-AA9D-4618-A949-C1B91AF43B1A}\` `\{F82B4EF1-93A9-4DDE-8015-F7950A1A6E31}\` `\{ddc05a5a-351a-4e06-8eaf-54ec1bc2dcea}\`

`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)

COM Object Hijacking Via Modification Of Default System CLSID Default Value

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_target_root`

Stage 2: `selection_target_builtin_clsid`

Stage 3: `selection_susp_location_1`

Stage 4: `selection_susp_location_2`

Indicators

Keyboard shortcuts

Search operators

COM Object Hijacking Via Modification Of Default System CLSID Default Value

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_target_root

Stage 2: selection_target_builtin_clsid

Stage 3: selection_susp_location_1

Stage 4: selection_susp_location_2

Indicators

Stage 0: `condition`

Stage 1: `selection_target_root`

Stage 2: `selection_target_builtin_clsid`

Stage 3: `selection_susp_location_1`

Stage 4: `selection_susp_location_2`