Devcon Execution Disabling VMware VMCI Device

Status: experimental
Severity: high
Log source: product windows, category process_creation
Author: Matt Anderson, Dray Agha, Anna Pham (Huntress)
Source: github.com/SigmaHQ/sigma

Detects execution of devcon.exe with commands that disable the VMware Virtual Machine Communication Interface (VMCI) device. This can be legitimate during VMware Tools troubleshooting or driver conflicts, but may also indicate malware attempting to hijack communication with the hardware via the VMCI device. This has been used to facilitate VMware ESXi vulnerability exploits to escape VMs and execute code on the ESXi host.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1543.003` Create or Modify System Process: Windows Service
Privilege Escalation	`T1543.003` Create or Modify System Process: Windows Service
Defense Impairment	`T1685` Disable or Modify Tools

Event coverage

Provider	Event	Title
Sysmon	Event ID 1	Process creation

Rule body yaml

title: Devcon Execution Disabling VMware VMCI Device
id: 85f520e7-6f5e-43ca-874c-222e5bf9c0de
status: experimental
description: |
    Detects execution of devcon.exe with commands that disable the VMware Virtual Machine Communication Interface (VMCI) device.
    This can be legitimate during VMware Tools troubleshooting or driver conflicts, but may also indicate malware attempting to hijack communication with the hardware via the VMCI device.
    This has been used to facilitate VMware ESXi vulnerability exploits to escape VMs and execute code on the ESXi host.
references:
    - https://learn.microsoft.com/en-us/windows-hardware/drivers/devtest/devcon
    - https://communities.vmware.com/t5/VMware-Workstation-Pro/VMCI-driver-issues/td-p/2866060
    - https://github.com/search?q=devcon+disable+VMWVMCIHOSTDEV
    - https://huntress.com/blog/esxi-vm-escape-exploit
author: Matt Anderson, Dray Agha, Anna Pham (Huntress)
date: 2026-01-02
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.defense-impairment
    - attack.t1543.003
    - attack.t1685
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\devcon.exe'
        - OriginalFileName: 'DevCon.exe'
    selection_action:
        CommandLine|contains: ' disable '
    selection_vmci_pci:
        CommandLine|contains:
            - '15AD&DEV_0740' # VMware VMCI PCI device (Vendor 0x15AD = VMware, Device 0x0740 = VMCI)
            - 'VMWVMCIHOSTDEV' # VMware VMCI root host device driver name
    condition: all of selection_*
falsepositives:
    - Legitimate VMware administration, Tools installation/uninstallation, or troubleshooting driver conflicts.
    - Automated scripts in virtualized environments for device cleanup.
level: high
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_devcon_disable_vmci_driver/info.yml

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_img`

selection_img:
    - Image|endswith: '\devcon.exe'
    - OriginalFileName: 'DevCon.exe'

Stage 2: `selection_action`

selection_action:
    CommandLine|contains: ' disable '

Stage 3: `selection_vmci_pci`

selection_vmci_pci:
    CommandLine|contains:
        - '15AD&DEV_0740'
        - 'VMWVMCIHOSTDEV'

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	`disable` corpus 2 (sigma 2) `15AD&DEV_0740` `VMWVMCIHOSTDEV`
`Image`	ends_with	`\devcon.exe`
`OriginalFileName`	eq	`DevCon.exe`

`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)

Devcon Execution Disabling VMware VMCI Device

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_action`

Stage 3: `selection_vmci_pci`

Indicators

Keyboard shortcuts

Search operators

Devcon Execution Disabling VMware VMCI Device

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_img

Stage 2: selection_action

Stage 3: selection_vmci_pci

Indicators

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_action`

Stage 3: `selection_vmci_pci`