Temporary ConnectWise xml File Activity (Windows Event Log)

Group by: _time, host
Source: github.com/anvilogic-forge/armory

ConnectWise ScreenConnect is a popular remote desktop solution. ConnectWise released an advisory detailing a critical authentication bypass vulnerability affecting ScreenConnect versions prior to 23.9.8. This use case detects when an XML file in the \Temp\ScreenConnect[version number]\ directory has been created, modified, or deleted. To enable detection of the file activities associated with the vulnerability, configure the Advanced Auditing policy to log successful Windows Event ID 4663 events, and set a System Access Control List (SACL) on the target directory to monitor file modifications. See Huntress article in references for detailed information.

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1133` External Remote Services
Persistence	`T1133` External Remote Services
Command & Control	`T1219` Remote Access Tools

References

Event coverage

Provider	Event	Title
Security-Auditing	Event ID 4663	An attempt was made to access an object.

Rule body yaml

id: '28096.51137'
title: Temporary ConnectWise xml File Activity
description: ConnectWise ScreenConnect is a popular remote desktop solution. ConnectWise
  released an advisory detailing a critical authentication bypass vulnerability affecting
  ScreenConnect versions prior to 23.9.8. This use case detects when an XML file in
  the \Temp\ScreenConnect\[version number]\ directory has been created, modified,
  or deleted. To enable detection of the file activities associated with the vulnerability,
  configure the Advanced Auditing policy to log successful Windows Event ID 4663 events,
  and set a System Access Control List (SACL) on the target directory to monitor file
  modifications. See Huntress article in references for detailed information.
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4663) OR
  "<EventID>4663<") "C:\\Windows\\Temp\\ScreenConnect\\" ".xml" | regex ObjectName="(?i)C:\x5cWindows\x5cTemp\x5c\ScreenConnect\x5c.+\.xml"
  | table _time, host, user, process, process_*, ObjectName | bin span=1s | stats
  values(*) as * by _time, host '
techniques:
- persistence:external remote services
- command-and-control:remote access software
- initial-access:external remote services
technique_id: 
- T1133
- T1219
data_category:
- File monitoring
- Windows event logs
references:
- https://www.huntress.com/blog/detection-guidance-for-connectwise-cwe-288-2
- https://www.connectwise.com/company/trust/security-bulletins/connectwise-screenconnect-23.9.8

Stages and Predicates

Stage 1: `search`

`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4663) OR "<EventID>4663<") "C:\\Windows\\Temp\\ScreenConnect\\" ".xml"

Stage 2: `regex`

| regex ObjectName="(?i)C:\x5cWindows\x5cTemp\x5c\ScreenConnect\x5c.+\.xml"

Stage 3: `table`

| table _time, host, user, process, process_*, ObjectName

Stage 4: `bucket`

| bin span=1s

Stage 5: `stats`

| stats values(*) as * by _time, host

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
`EventCode`	eq	`4663` corpus 34 (splunk 29, kusto 5)
`ObjectName`	regex_match	`"(?i)C:\x5cWindows\x5cTemp\x5c\ScreenConnect\x5c.+.xml"`

Search terms

Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.

Stage	Term
1	`TERM`
1	`"<EventID>4663<"`
1	`"C:\\Windows\\Temp\\ScreenConnect\\"`
1	`".xml"`

`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)

Temporary ConnectWise xml File Activity (Windows Event Log)

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

Stages and Predicates

Stage 1: `search`

Stage 2: `regex`

Stage 3: `table`

Stage 4: `bucket`

Stage 5: `stats`

Indicators

Search terms

Keyboard shortcuts

Search operators

Temporary ConnectWise xml File Activity (Windows Event Log)

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

Stages and Predicates

Stage 1: search

Stage 2: regex

Stage 3: table

Stage 4: bucket

Stage 5: stats

Indicators

Search terms

Stage 1: `search`

Stage 2: `regex`

Stage 3: `table`

Stage 4: `bucket`

Stage 5: `stats`