Cisco IOS XE Log Clearing Sequence With Optional Loopback Removal

Status: production
Severity: low
Group by: _time, dest
Author: Nasreddine Bencherchali
Source: github.com/splunk/security_content

This analytic detects Cisco IOS-XE command sequences where show logging, clear logging, and exit occur within a short period. It also detects the pattern where a loopback interface is removed before clearing logs and exiting.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1070.001` Indicator Removal: Clear Windows Event Logs, `T1562` Impair Defenses

Rule body splunk

name: Cisco IOS XE Log Clearing Sequence With Optional Loopback Removal
id: e20a6709-5f2c-4508-83fb-b3af6f705717
version: 1
creation_date: '2026-05-19'
modification_date: '2026-05-20'
author: Nasreddine Bencherchali
status: production
type: Anomaly
description: |
    This analytic detects Cisco IOS-XE command sequences where show logging, clear logging, and exit occur within a short period.
    It also detects the pattern where a loopback interface is removed before clearing logs and exiting.
data_source:
    - Cisco IOS Logs
search: |-
    `cisco_ios`
    facility IN ("AAA", "HA_EM", "PARSER")
    mnemonic IN ("AAA_ACCOUNTING_MESSAGE", "LOG", "CFGLOG_LOGGEDCMD")
    message_text IN ("*show logging*", "*clear logging*", "*exit*", "*no interface Loopback*")
    
    | eval cmd=lower(coalesce(command, message_text))
    | eval event_type=case(
                like(cmd, "%show logging%"), "show_logging",
                like(cmd, "%clear logging%"), "clear_logging",
                like(cmd, "%exit%"), "exit",
                like(cmd, "%no interface loopback%"), "remove_loopback"
            )
    | where isnotnull(event_type)
    | eval dest=coalesce(host, dvc, dest, "unknown")
    | bin _time span=2m
    | stats count min(_time) as firstTime
                  max(_time) as lastTime
                  values(event_type) as event_types
                  values(message_text) as message_text
                  values(cmd) as cmd
      by _time dest
    | where mvfind(event_types, "clear_logging") >= 0
            AND
            mvfind(event_types, "exit") >= 0
            AND
            (
                mvfind(event_types, "show_logging") >= 0
                OR
                mvfind(event_types, "remove_loopback") >= 0
            )
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `cisco_ios_xe_log_clearing_sequence_with_optional_loopback_removal_filter`
how_to_implement: |
    Use the Cisco Catalyst Add-on for Splunk (https://splunkbase.splunk.com/app/7538) to Ingest Cisco IOS-XE syslog with sourcetype "cisco:ios".
    Command visibility requires AAA command accounting, archive/config logging for configuration commands, or EEM catchall logging.
known_false_positives: |
    No false positives have been identified at this time.
references:
    - https://www.cisa.gov/news-events/cybersecurity-advisories/aa25-239a
    - https://blog.talosintelligence.com/salt-typhoon-analysis/
drilldown_searches:
    - name: View the detection results for - "$dest$"
      search: '%original_detection_search% | search  dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: Cisco IOS-XE log clearing sequence was observed on $dest$.
threat_objects: []
analytic_story:
    - Salt Typhoon
asset_type: Network
mitre_attack_id:
    - T1070.001
    - T1562
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: application
security_domain: network
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/emerging_threats/SaltTyphoon/salttyphoon_cisco.log
          source: ctb:catalyst:syslog
          sourcetype: cisco:ios
      test_type: unit

Stages and Predicates

Stage 1: `search`

`cisco_ios`
facility IN ("AAA", "HA_EM", "PARSER")
mnemonic IN ("AAA_ACCOUNTING_MESSAGE", "LOG", "CFGLOG_LOGGEDCMD")
message_text IN ("*show logging*", "*clear logging*", "*exit*", "*no interface Loopback*")

Stage 2: `eval`

| eval cmd=lower(coalesce(command, message_text))

Stage 3: `eval`

| eval event_type=case(
            like(cmd, "%show logging%"), "show_logging",
            like(cmd, "%clear logging%"), "clear_logging",
            like(cmd, "%exit%"), "exit",
            like(cmd, "%no interface loopback%"), "remove_loopback"
        )

event_type =

iflike(cmd, "%show logging%")"show_logging"

eliflike(cmd, "%clear logging%")"clear_logging"

eliflike(cmd, "%exit%")"exit"

else"remove_loopback"

Stage 4: `where`

| where isnotnull(event_type)

Stage 5: `eval`

| eval dest=coalesce(host, dvc, dest, "unknown")

Stage 6: `bucket`

| bin _time span=2m

Stage 7: `stats`

| stats count min(_time) as firstTime
              max(_time) as lastTime
              values(event_type) as event_types
              values(message_text) as message_text
              values(cmd) as cmd
  by _time dest

Stage 8: `where`

| where mvfind(event_types, "clear_logging") >= 0
        AND
        mvfind(event_types, "exit") >= 0
        AND
        (
            mvfind(event_types, "show_logging") >= 0
            OR
            mvfind(event_types, "remove_loopback") >= 0
        )

Stage 9: `search`

| `security_content_ctime(firstTime)`

Stage 10: `search`

| `security_content_ctime(lastTime)`

Stage 11: `search`

| `cisco_ios_xe_log_clearing_sequence_with_optional_loopback_removal_filter`

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
`event_type`	is_not_null	(no value, null check)
`facility`	in	`"AAA"` `"HA_EM"` `"PARSER"`
`message_text`	in	`"clear logging"` `"exit"` `"no interface Loopback"` `"show logging"`
`mnemonic`	in	`"AAA_ACCOUNTING_MESSAGE"` `"CFGLOG_LOGGEDCMD"` `"LOG"`
`sourcetype`	eq	`cisco:ios`

`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)

Cisco IOS XE Log Clearing Sequence With Optional Loopback Removal

MITRE ATT&CK coverage

Rule body splunk

Stages and Predicates

Stage 1: `search`

Stage 2: `eval`

Stage 3: `eval`

Stage 4: `where`

Stage 5: `eval`

Stage 6: `bucket`

Stage 7: `stats`

Stage 8: `where`

Stage 9: `search`

Stage 10: `search`

Stage 11: `search`

Indicators

Keyboard shortcuts

Search operators

Cisco IOS XE Log Clearing Sequence With Optional Loopback Removal

MITRE ATT&CK coverage

Rule body splunk

Stages and Predicates

Stage 1: search

Stage 2: eval

Stage 3: eval

Stage 4: where

Stage 5: eval

Stage 6: bucket

Stage 7: stats

Stage 8: where

Stage 9: search

Stage 10: search

Stage 11: search

Indicators

Stage 1: `search`

Stage 2: `eval`

Stage 3: `eval`

Stage 4: `where`

Stage 5: `eval`

Stage 6: `bucket`

Stage 7: `stats`

Stage 8: `where`

Stage 9: `search`

Stage 10: `search`

Stage 11: `search`