Connection to Commonly Abused Web Services
editConnection to Commonly Abused Web Services
editAdversaries may implement command and control (C2) communications that use common web services to hide their activity. This attack technique is typically targeted at an organization and uses web services common to the victim network, which allows the adversary to blend into legitimate traffic activity. These popular services are typically targeted since they have most likely been used before compromise, which helps malicious traffic blend in.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
Severity: low
Risk score: 21
Runs every: 5 minutes
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Command and Control
Version: 8 (version history)
Added (Elastic Stack release): 7.11.0
Last modified (Elastic Stack release): 8.2.0
Rule authors: Elastic
Rule license: Elastic License v2
Investigation guide
edit## Triage and analysis ### Investigating Connection to Commonly Abused Web Services Adversaries may use an existing, legitimate external Web service as a means for relaying data to/from a compromised system. Popular websites and social media acting as a mechanism for C2 may give a significant amount of cover due to the likelihood that hosts within a network are already communicating with them prior to a compromise. This rule looks for processes outside known legitimate program locations communicating with a list of services that can be abused for exfiltration or command and control. #### Possible investigation steps - Investigate the script execution chain (parent process tree). - Investigate other alerts related to the user/host in the last 48 hours. - Verify whether the digital signature exists in the executable. - Identify the kind of the operation (upload, download, tunneling, etc.). - Use a sandboxed malware analysis system to perform analysis on the executable. - Use the PowerShell Get-FileHash cmdlet to get the SHA-256 hash value of the file. - Search for the existence of this file in resources like VirusTotal, Hybrid-Analysis, CISCO Talos, Any.run, etc. ### False positive analysis - This rule has a high chance to produce false positives because it detects communication with legitimate services. Noisy false positives can be added as exceptions. ### Response and remediation - Initiate the incident response process based on the outcome of the triage. - Isolate the involved host to prevent further post-compromise behavior. - If the triage identified malware, search the environment for additional compromised hosts. - Implement any temporary network rules, procedures, and segmentation required to contain the malware.
Rule query
editnetwork where network.protocol == "dns" and process.name != null and user.id not in ("S-1-5-18", "S-1-5-19", "S-1-5-20") and /* Add new WebSvc domains here */ dns.question.name : ( "raw.githubusercontent.*", "*.pastebin.*", "*drive.google.*", "*docs.live.*", "*api.dropboxapi.*", "*dropboxusercontent.*", "*onedrive.*", "*4shared.*", "*.file.io", "*filebin.net", "*slack-files.com", "*ghostbin.*", "*ngrok.*", "*portmap.*", "*serveo.net", "*localtunnel.me", "*pagekite.me", "*localxpose.io", "*notabug.org", "rawcdn.githack.*", "paste.nrecom.net", "zerobin.net", "controlc.com", "requestbin.net", "cdn.discordapp.com", "discordapp.com", "discord.com" ) and /* Insert noisy false positives here */ not process.executable : ( "?:\\Program Files\\*.exe", "?:\\Program Files (x86)\\*.exe", "?:\\Windows\\System32\\WWAHost.exe", "?:\\Windows\\System32\\smartscreen.exe", "?:\\Windows\\System32\\MicrosoftEdgeCP.exe", "?:\\ProgramData\\Microsoft\\Windows Defender\\Platform\\*\\MsMpEng.exe", "?:\\Users\\*\\AppData\\Loc al\\Google\\Chrome\\Application\\chrome.exe", "?:\\Users\\*\\AppData\\Local\\Programs\\Fiddler\\Fiddler.exe", "?:\\Users\\*\\AppData\\Local\\Programs\\Microsoft VS Code\\Code.exe", "?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\OneDrive.exe", "?:\\Windows\\system32\\mobsync.exe", "?:\\Windows\\SysWOW64\\mobsync.exe", "?:\\Users\\*\\AppData\\Local\\Discord\\-*\\Discord.exe" )
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Command and Control
- ID: TA0011
- Reference URL: https://attack.mitre.org/tactics/TA0011/
-
Technique:
- Name: Web Service
- ID: T1102
- Reference URL: https://attack.mitre.org/techniques/T1102/
-
Tactic:
- Name: Exfiltration
- ID: TA0010
- Reference URL: https://attack.mitre.org/tactics/TA0010/
-
Technique:
- Name: Exfiltration Over Web Service
- ID: T1567
- Reference URL: https://attack.mitre.org/techniques/T1567/
Rule version history
edit- Version 8 (8.2.0 release)
-
- Formatting only
- Version 7 (8.1.0 release)
-
- Formatting only
- Version 6 (8.0.0 release)
-
-
Updated query, changed from:
network where network.protocol == "dns" and process.name != null and user.id not in ("S-1-5-18", "S-1-5-19", "S-1-5-20") and /* Add new WebSvc domains here */ dns.question.name : ( "raw.githubusercontent.*", "*.pastebin.*", "*drive.google.*", "*docs.live.*", "*api.dropboxapi.*", "*dropboxusercontent.*", "*onedrive.*", "*4shared.*", "*.file.io", "*filebin.net", "*slack-files.com", "*ghostbin.*", "*ngrok.*", "*portmap.*", "*serveo.net", "*localtunnel.me", "*pagekite.me", "*localxpose.io", "*notabug.org", "rawcdn.githack.*", "paste.nrecom.net", "zerobin.net", "controlc.com", "requestbin.net" ) and /* Insert noisy false positives here */ not process.executable : ( "?:\\Program Files\\*.exe", "?:\\Program Files (x86)\\*.exe", "?:\\Windows\\System32\\WWAHost.exe", "?:\\Windows\\System32\\smartscreen.exe", "?:\\Windows\\System32\\MicrosoftEdgeCP.exe", "?:\\ProgramData\\Microsoft\\Windows Defender\\Platform\\*\\MsMpEng.exe", "?:\\Users\\*\\AppData\\Loc al\\Google\\Chrome\\Application\\chrome.exe", "?:\\Users\\*\\AppData\\Local\\Programs\\Fiddler\\Fiddler.exe", "?:\\Users\\*\\AppData\\Local\\Programs\\Microsoft VS Code\\Code.exe", "?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\OneDrive.exe", "?:\\Windows\\system32\\mobsync.exe", "?:\\Windows\\SysWOW64\\mobsync.exe" )
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- Version 5 (7.16.0 release)
-
- Formatting only
- Version 4 (7.13.0 release)
-
-
Updated query, changed from:
network where network.protocol == "dns" and /* Add new WebSvc domains here */ dns.question.name : ( "*.githubusercontent.*", "*.pastebin.*", "*drive.google.*", "*docs.live.*", "*api.dropboxapi.*", "*dropboxusercontent.*", "*onedrive.*", "*4shared.*", "*.file.io", "*filebin.net", "*slack-files.com", "*ghostbin.*", "*ngrok.*", "*portmap.*", "*serveo.net", "*localtunnel.me", "*pagekite.me", "*localxpose.io", "*notabug.org" ) and /* Insert noisy false positives here */ not process.name : ( "MicrosoftEdgeCP.exe", "MicrosoftEdge.exe", "iexplore.exe", "chrome.exe", "msedge.exe", "opera.exe", "firefox.exe", "Dropbox.exe", "slack.exe", "svchost.exe", "thunderbird.exe", "outlook.exe", "OneDrive.exe" )
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- Version 3 (7.12.0 release)
-
-
Updated query, changed from:
network where network.protocol == "dns" and /* Add new WebSvc domains here */ wildcard(dns.question.name, "*.githubusercontent.*", "*.pastebin.*", "*drive.google.*", "*docs.live.*", "*api.dropboxapi.*", "*dropboxusercontent.*", "*onedrive.*", "*4shared.*", "*.file.io", "*filebin.net", "*slack-files.com", "*ghostbin.*", "*ngrok.*", "*portmap.*", "*serveo.net", "*localtunnel.me", "*pagekite.me", "*localxpose.io", "*notabug.org" ) and /* Insert noisy false positives here */ not process.name in ("MicrosoftEdgeCP.exe", "MicrosoftEdge.exe", "iexplore.exe", "chrome.exe", "msedge.exe", "opera.exe", "firefox.exe", "Dropbox.exe", "slack.exe", "svchost.exe", "thunderbird.exe", "outlook.exe", "OneDrive.exe")
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- Version 2 (7.11.2 release)
-
- Formatting only