Potential Ransomware activity related to Cobalt Strike

Status: available
Severity: high
Time window: 1d
Group by: AlertId, AlertTime, DeviceId, Title
Source: github.com/Azure/Azure-Sentinel

This query searches for alerts related to suspected ransomware and Cobalt Strike activity, a tool used in numerous ransomware campaigns. It looks for alerts that indicate potential ransomware activity, such as attempts to clear security event logs, delete backup files, and execute Cobalt Strike malware.

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059` Command and Scripting Interpreter
Persistence	`T1078` Valid Accounts
Stealth	`T1070` Indicator Removal, `T1078` Valid Accounts
Impact	`T1490` Inhibit System Recovery

Rule body kusto

id: 4bd9ce9d-8586-4beb-8fdb-bd018cacbe7d
name: Potential Ransomware activity related to Cobalt Strike
description: |
  This query searches for alerts related to suspected ransomware and Cobalt Strike activity, a tool used in numerous ransomware campaigns. It looks for alerts that indicate potential ransomware activity, such as attempts to clear security event logs, delete backup files, and execute Cobalt Strike malware.
severity: High
status: Available
requiredDataConnectors:
  - connectorId: MicrosoftThreatProtection
    dataTypes:
      - AlertInfo
      - AlertEvidence
      - DeviceLogonEvents
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Execution
  - Persistence
  - DefenseEvasion
  - Impact
relevantTechniques:
  - T1059
  - T1078
  - T1070
  - T1490
query: |
  // Look for sc.exe disabling services
  AlertInfo 
  // Attempts to clear security event logs. 
  | where Title in("Event log was cleared", 
  // List alerts flagging attempts to delete backup files. 
  "File backups were deleted", 
  // Potential Cobalt Strike activity - Note that other threat activity can also 
  // trigger alerts for suspicious decoded content 
  "Suspicious decoded content", 
  // Cobalt Strike activity 
  "\'Atosev\' malware was detected", 
  "\'Ploty\' malware was detected", 
  "\'Bynoco\' malware was detected",
  "\'Cobaltstrike\' malware was detected",
  "Echo command over pipe on localhost",
  "Known attack framework activity was observed",
  "An active \'Cobaltstrike\' malware was detected",
  "Suspicious \'CobaltStrike\' behavior was prevented",
  "Suspicious process launch by Rundll32.exe") 
  | extend AlertTime = TimeGenerated | distinct AlertTime, AlertId, Title 
  | join AlertEvidence on $left.AlertId == $right.AlertId
  | summarize by DeviceId, AlertTime, Title, AlertId
  // Get device IDs
  | join DeviceLogonEvents on $left.DeviceId == $right.DeviceId 
  // Creating 10 day Window surrounding alert activity 
  | where TimeGenerated < AlertTime + 12h and TimeGenerated > AlertTime - 12h // Projecting specific columns 
  | project Title, DeviceName, DeviceId, TimeGenerated, LogonType, AccountDomain, AccountName, AccountSid, AlertTime, AlertId, RemoteIP, RemoteDeviceName
  | extend AccountFullName = tostring(strcat(AccountDomain, "\\", AccountName))
  | extend HostName = iff(DeviceName has '.', substring(DeviceName, 0, indexof(DeviceName, '.')), DeviceName)
  | extend DnsDomain = iff(DeviceName has '.', substring(DeviceName, indexof(DeviceName, '.') + 1), "")
entityMappings:  
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: DeviceName
      - identifier: HostName
        columnName: HostName
      - identifier: DnsDomain
        columnName: DnsDomain
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: AccountFullName
      - identifier: Name
        columnName: AccountName
      - identifier: DnsDomain
        columnName: AccountDomain
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: RemoteIP
version: 1.0.1
kind: Scheduled

Stages and Predicates

Stage 1: `source`

AlertInfo

Stage 2: `where`

| where Title in("Event log was cleared", 
"File backups were deleted", 
"Suspicious decoded content", 
"\'Atosev\' malware was detected", 
"\'Ploty\' malware was detected", 
"\'Bynoco\' malware was detected",
"\'Cobaltstrike\' malware was detected",
"Echo command over pipe on localhost",
"Known attack framework activity was observed",
"An active \'Cobaltstrike\' malware was detected",
"Suspicious \'CobaltStrike\' behavior was prevented",
"Suspicious process launch by Rundll32.exe")

Stage 3: `extend`

| extend AlertTime = TimeGenerated

Stage 4: `distinct`

| distinct AlertTime, AlertId, Title

Stage 5: `join`

| join AlertEvidence on $left.AlertId == $right.AlertId

Stage 6: `summarize`

| summarize by DeviceId, AlertTime, Title, AlertId

Stage 7: `join`

| join DeviceLogonEvents on $left.DeviceId == $right.DeviceId

Stage 8: `where` where TimeGenerated - AlertTime < 12h

| where TimeGenerated < AlertTime + 12h and TimeGenerated > AlertTime - 12h

Stage 9: `project`

| project Title, DeviceName, DeviceId, TimeGenerated, LogonType, AccountDomain, AccountName, AccountSid, AlertTime, AlertId, RemoteIP, RemoteDeviceName

Stage 10: `extend` (3 consecutive steps)

| extend AccountFullName = tostring(strcat(AccountDomain, "\\", AccountName))
| extend HostName = iff(DeviceName has '.', substring(DeviceName, 0, indexof(DeviceName, '.')), DeviceName)
| extend DnsDomain = iff(DeviceName has '.', substring(DeviceName, indexof(DeviceName, '.') + 1), "")

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
`Title`	in	`An active \'Cobaltstrike\' malware was detected` transforms: `cased` `Echo command over pipe on localhost` transforms: `cased` `Event log was cleared` transforms: `cased` `File backups were deleted` transforms: `cased` `Known attack framework activity was observed` transforms: `cased` `Suspicious \'CobaltStrike\' behavior was prevented` transforms: `cased` `Suspicious decoded content` transforms: `cased` `Suspicious process launch by Rundll32.exe` transforms: `cased` `\'Atosev\' malware was detected` transforms: `cased` `\'Bynoco\' malware was detected` transforms: `cased` `\'Cobaltstrike\' malware was detected` transforms: `cased` `\'Ploty\' malware was detected` transforms: `cased`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`AccountDomain`	`project`
`AccountName`	`project`
`AccountSid`	`project`
`AlertId`	`project`
`AlertTime`	`project`
`DeviceId`	`project`
`DeviceName`	`project`
`LogonType`	`project`
`RemoteDeviceName`	`project`
`RemoteIP`	`project`
`TimeGenerated`	`project`
`Title`	`project`
`AccountFullName`	`extend`
`HostName`	`extend`
`DnsDomain`	`extend`

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`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)

Potential Ransomware activity related to Cobalt Strike

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `distinct`

Stage 5: `join`

Stage 6: `summarize`

Stage 7: `join`

Stage 8: `where` where TimeGenerated - AlertTime < 12h

Stage 9: `project`

Stage 10: `extend` (3 consecutive steps)

Indicators

Output fields

Keyboard shortcuts

Search operators

Potential Ransomware activity related to Cobalt Strike

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: extend

Stage 4: distinct

Stage 5: join

Stage 6: summarize

Stage 7: join

Stage 8: where where TimeGenerated - AlertTime < 12h

Stage 9: project

Stage 10: extend (3 consecutive steps)

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `distinct`

Stage 5: `join`

Stage 6: `summarize`

Stage 7: `join`

Stage 8: `where` where TimeGenerated - AlertTime < 12h

Stage 9: `project`

Stage 10: `extend` (3 consecutive steps)