Rundll32 DNSQuery

 Original Source: [splunk source]
Name:Rundll32 DNSQuery
id:f1483f5e-ee29-11eb-9d23-acde48001122
version:13
date:None
author:Teoderick Contreras, Splunk
status:production
type:TTP
Description:The following analytic detects a suspicious `rundll32.exe` process making HTTP connections and performing DNS queries to web domains. It leverages Sysmon EventCode 22 logs to identify these activities. This behavior is significant as it is commonly associated with IcedID malware, where `rundll32.exe` checks internet connectivity and communicates with C&C servers to download configurations and other components. If confirmed malicious, this activity could allow attackers to establish persistence, download additional payloads, and exfiltrate sensitive data, posing a severe threat to the network.
Data_source:
  • -Sysmon EventID 22
search:`sysmon` EventCode=22 process_name="rundll32.exe"

| stats count min(_time) as firstTime max(_time) as lastTime
BY answer answer_count dvc
process_exec process_guid process_name
query query_count reply_code_id
signature signature_id src
user_id vendor_product QueryName
QueryResults QueryStatus

| `security_content_ctime(firstTime)`

| `security_content_ctime(lastTime)`

| `rundll32_dnsquery_filter`


how_to_implement:To successfully implement this search, you need to be ingesting logs with the process name and eventcode = 22 dnsquery executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA. Tune and filter known instances where renamed rundll32.exe may be used.
known_false_positives:No false positives have been identified at this time.
References:
  -https://any.run/malware-trends/icedid
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'
analytic_story:['IcedID', 'Living Off The Land']

asset_type:Endpoint

mitre_attack_id:['T1218.011']

product:['Splunk Enterprise', 'Splunk Enterprise Security', 'Splunk Cloud']

category:network

security_domain:endpoint

tags:

tests:
 name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/icedid/inf_icedid/windows-sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
 test_type:'unit'
manual_test:None

Related Analytic Stories


IcedID

Living Off The Land