Windows Abused Web Services

Name:Windows Abused Web Services
id:01f0aef4-8591-4daa-a53d-0ed49823b681
version:10
date:2026-03-16
author:Teoderick Contreras, Splunk
status:production
type:Anomaly
Description:The following analytic detects a suspicious process making DNS queries to known, abused web services such as text-paste sites, VoIP, secure tunneling, instant messaging, and digital distribution platforms. This detection leverages Sysmon logs with Event ID 22, focusing on specific query names. This activity is significant as it may indicate an adversary attempting to download malicious files, a common initial access technique. If confirmed malicious, this could lead to unauthorized code execution, data exfiltration, or further compromise of the target host.
Data_source:

• -Sysmon EventID 22

search:`sysmon`
EventCode=22
QueryName IN (
"*//objects.githubusercontent.com*",
"*anonfiles.com*",
"*cdn.discordapp.com*",
"*ddns.net*",
"*dl.dropboxusercontent.com*",
"*duckdns.org*",
"*ghostbin.co*",
"*glitch.me*",
"*gofile.io*",
"*hastebin.com*",
"*mediafire.com*",
"*mega.nz*",
"*ngrok.io*",
"*onrender.com*",
"*pages.dev*",
"*paste.ee*",
"*pastebin.com*",
"*pastebin.pl*",
"*pasteio.com*",
"*pastetext.net*",
"*privatlab.com*",
"*privatlab.net*",
"*send.exploit.in*",
"*sendspace.com*",
"*storage.googleapis.com*",
"*storjshare.io*",
"*supabase.co*",
"*temp.sh*",
"*textbin*",
"*transfer.sh*",
"*trycloudflare.com*",
"*ufile.io*",
"*w3spaces.com*",
"*workers.dev*"
)
| eval answer=coalesce(answer,"none")
| eval answer_count=coalesce(answer_count,0)
| rename dvc as dest
| stats min(_time) as firstTime max(_time) as lastTime count
BY answer answer_count dest 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)`
| `windows_abused_web_services_filter`

how_to_implement:This detection relies on sysmon logs with the Event ID 22, DNS Query. We suggest you run this detection at least once a day over the last 14 days.
known_false_positives:Noise and false positive can be seen if the following instant messaging is allowed to use within corporate network. In this case, a filter is needed.
References:
  -https://malpedia.caad.fkie.fraunhofer.de/details/win.njrat
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 ("$dest$") starthoursago=168 | 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:'$info_min_time$'
 latest_offset:'$info_max_time$'
tags:
  analytic_story:
    - 'NjRAT'
    - 'CISA AA24-241A'
    - 'Malicious Inno Setup Loader'
    - 'BlankGrabber Stealer'
  asset_type:Endpoint
  mitre_attack_id:
    - 'T1102'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  security_domain:endpoint

tests:
 name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1102/njrat_ngrok_connection/ngrok.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1071.004/upload_files_dns/upload_files.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
manual_test:None