Clipboard Collection of Image Data with Xclip Tool

Status: test
Severity: low
Log source: product linux, service auditd
Author: Pawel Mazur
Source: github.com/SigmaHQ/sigma

Detects attempts to collect image data stored in the clipboard from users with the usage of xclip tool. Xclip has to be installed. Highly recommended using rule on servers, due to high usage of clipboard utilities on user workstations.

MITRE ATT&CK coverage

Tactic	Techniques
Collection	`T1115` Clipboard Data

Event coverage

Provider	Event
Linux-Auditd	Event ID 1309

Rule body yaml

title: Clipboard Collection of Image Data with Xclip Tool
id: f200dc3f-b219-425d-a17e-c38467364816
status: test
description: |
  Detects attempts to collect image data stored in the clipboard from users with the usage of xclip tool.
  Xclip has to be installed.
  Highly recommended using rule on servers, due to high usage of clipboard utilities on user workstations.
references:
    - https://linux.die.net/man/1/xclip
author: 'Pawel Mazur'
date: 2021-10-01
modified: 2022-10-09
tags:
    - attack.collection
    - attack.t1115
logsource:
    product: linux
    service: auditd
detection:
    selection:
        type: EXECVE
        a0: xclip
        a1:
            - '-selection'
            - '-sel'
        a2:
            - clipboard
            - clip
        a3: '-t'
        a4|startswith: 'image/'
        a5: '-o'
    condition: selection
falsepositives:
    - Legitimate usage of xclip tools
level: low

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    type: EXECVE
    a0: xclip
    a1:
        - '-selection'
        - '-sel'
    a2:
        - clipboard
        - clip
    a3: '-t'
    a4|startswith: 'image/'
    a5: '-o'

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
`a0`	eq	`xclip`
`a1`	eq	`-sel` `-selection`
`a2`	eq	`clip` `clipboard`
`a3`	eq	`-t`
`a4`	starts_with	`image/`
`a5`	eq	`-o`
`type`	eq	`EXECVE`

`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)

Clipboard Collection of Image Data with Xclip Tool

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection`

Indicators

Keyboard shortcuts

Search operators

Clipboard Collection of Image Data with Xclip Tool

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection

Indicators

Stage 0: `condition`

Stage 1: `selection`