Detection: Windows Abused Web Services

Updated Date: 2026-03-16 ID: 01f0aef4-8591-4daa-a53d-0ed49823b681 Author: Teoderick Contreras, Splunk Type: Anomaly Product: Splunk Enterprise Security

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.

Search

 1`sysmon`
 2EventCode=22
 3QueryName IN (
 4    "*//objects.githubusercontent.com*",
 5    "*anonfiles.com*",
 6    "*cdn.discordapp.com*",
 7    "*ddns.net*",
 8    "*dl.dropboxusercontent.com*",
 9    "*duckdns.org*",
10    "*ghostbin.co*",
11    "*glitch.me*",
12    "*gofile.io*",
13    "*hastebin.com*",
14    "*mediafire.com*",
15    "*mega.nz*",
16    "*ngrok.io*",
17    "*onrender.com*",
18    "*pages.dev*",
19    "*paste.ee*",
20    "*pastebin.com*",
21    "*pastebin.pl*",
22    "*pasteio.com*",
23    "*pastetext.net*",
24    "*privatlab.com*",
25    "*privatlab.net*",
26    "*send.exploit.in*",
27    "*sendspace.com*",
28    "*storage.googleapis.com*",
29    "*storjshare.io*",
30    "*supabase.co*",
31    "*temp.sh*",
32    "*textbin*",
33    "*transfer.sh*",
34    "*trycloudflare.com*",
35    "*ufile.io*",
36    "*w3spaces.com*",
37    "*workers.dev*"
38)
39
40| eval answer=coalesce(answer,"none")
41
42| eval answer_count=coalesce(answer_count,0)
43
44| rename dvc as dest
45
46| stats  min(_time) as firstTime max(_time) as lastTime count
47    BY answer answer_count dest process_exec process_guid
48       process_name query query_count reply_code_id signature
49       signature_id src user_id vendor_product
50       QueryName QueryResults QueryStatus
51
52| `security_content_ctime(firstTime)`
53
54| `security_content_ctime(lastTime)`
55
56| `windows_abused_web_services_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 22	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
windows_abused_web_services_filter	`search *`

windows_abused_web_services_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1102	Web Service	Command And Control

Command and Control

DE.AE

CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Risk Event	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

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.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

A network connection on known abused web services [$QueryName$] from [$dest$]

Risk Object	Risk Object Type	Risk Score	Threat Objects
dest	system	20	process_name

References

https://malpedia.caad.fkie.fraunhofer.de/details/win.njrat

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 10