Detect Virtual Private Server in Splunk
Adversaries may rent Virtual Private Servers (VPSs) to stage malicious infrastructure including command-and-control (C2) servers, phishing pages, payload delivery endpoints, and exfiltration destinations. VPS providers offer rapid provisioning, geographic flexibility, and—when chosen carefully—minimal registration requirements, making attribution difficult. Because VPS-hosted IPs typically carry commercial hosting ASN reputation rather than residential or known-malicious reputation, they can evade naive geo-blocking and ASN-based controls. Real-world actors documented using this technique include Gamaredon, APT28, LAPSUS$, Ember Bear (GRU Unit 29155), HAFNIUM, APT42, Moonstone Sleet, and Contagious Interview. Detection from a defender perspective focuses on three observable effects: outbound C2 beaconing FROM compromised endpoints TO VPS-hosted IPs, inbound attack traffic (scanning, exploit delivery, phishing redirectors) FROM VPS IP ranges, and identity-based signals such as authentication attempts from datacenter IP space. Because T1583.003 is a Resource Development technique (TA0042), it is not directly observable on victim endpoints—detection is necessarily inferential, relying on behavioral patterns that betray VPS-based infrastructure in use.
MITRE ATT&CK
- Tactic
- Resource Development
- Technique
- T1583 Acquire Infrastructure
- Sub-technique
- T1583.003 Virtual Private Server
- Canonical reference
- https://attack.mitre.org/techniques/T1583/003/
SPL Detection Query
index=wineventlog sourcetype="XmlWinEventLog:Microsoft-Windows-Sysmon/Operational" EventCode=3
NOT (DestinationIp="10.*"
OR DestinationIp="172.16.*" OR DestinationIp="172.17.*" OR DestinationIp="172.18.*"
OR DestinationIp="172.19.*" OR DestinationIp="172.20.*" OR DestinationIp="172.21.*"
OR DestinationIp="172.22.*" OR DestinationIp="172.23.*" OR DestinationIp="172.24.*"
OR DestinationIp="172.25.*" OR DestinationIp="172.26.*" OR DestinationIp="172.27.*"
OR DestinationIp="172.28.*" OR DestinationIp="172.29.*" OR DestinationIp="172.30.*"
OR DestinationIp="172.31.*"
OR DestinationIp="192.168.*"
OR DestinationIp="127.*"
OR DestinationIp="::1"
OR DestinationIp="169.254.*")
NOT (Image="*\\chrome.exe"
OR Image="*\\firefox.exe"
OR Image="*\\msedge.exe"
OR Image="*\\MicrosoftEdgeCP.exe"
OR Image="*\\iexplore.exe"
OR Image="*\\brave.exe"
OR Image="*\\opera.exe"
OR Image="*\\svchost.exe"
OR Image="*\\MsMpEng.exe"
OR Image="*\\wuauclt.exe"
OR Image="*\\TrustedInstaller.exe"
OR Image="*\\teams.exe"
OR Image="*\\OneDrive.exe")
| bin _time span=1h
| stats
count as ConnectionCount,
dc(DestinationPort) as UniqueDestPorts,
values(DestinationPort) as DestPorts,
dc(DestinationIp) as UniqueDestIPs,
earliest(_time) as FirstSeen,
latest(_time) as LastSeen
by _time, host, User, Image, CommandLine, DestinationIp
| where ConnectionCount >= 12
| eval ConnectionsPerMinute=round(ConnectionCount / 60.0, 2)
| eval BeaconRisk=case(
ConnectionCount >= 50 AND UniqueDestPorts <= 1, "CRITICAL - Highly Regular Single-Port Beaconing",
ConnectionCount >= 30 AND UniqueDestPorts <= 2, "HIGH - Low Port Variance Repetitive Connections",
ConnectionCount >= 20, "MEDIUM - Elevated Outbound Connection Frequency",
ConnectionCount >= 12, "LOW - Above Threshold Outbound Frequency",
1=1, "INFO")
| where BeaconRisk != "INFO"
| eval RiskScore=case(
match(BeaconRisk, "CRITICAL"), 4,
match(BeaconRisk, "HIGH"), 3,
match(BeaconRisk, "MEDIUM"), 2,
1)
| table _time, host, User, Image, CommandLine, DestinationIp, ConnectionCount,
ConnectionsPerMinute, UniqueDestPorts, DestPorts, BeaconRisk, RiskScore
| sort - RiskScore, - ConnectionCountDetects C2 beaconing patterns to VPS-hosted external IPs using Sysmon Event ID 3 (Network Connection). Excludes all RFC1918 private ranges and known legitimate browser and system processes. Connections are bucketed into hourly windows and aggregated by destination IP and initiating process. A risk tier is assigned based on connection frequency and port variance: low port variance combined with high connection frequency is the strongest beacon indicator. The ConnectionsPerMinute field helps analysts quickly assess the regularity of the pattern. False positives should be suppressed by adding known-good management tool processes to the exclusion list.
Data Sources
Required Sourcetypes
False Positives & Tuning
- Software telemetry and update agents making periodic check-ins to cloud endpoints on fixed intervals — add process names to the NOT IMAGE exclusion block
- Monitoring agents (Splunk UF, Elastic, Datadog, Zabbix) maintaining persistent heartbeat connections to cloud-hosted collection infrastructure
- Remote access or VPN clients (GlobalProtect, AnyConnect) that keep persistent tunnels alive with regular keepalive packets
- CI/CD tooling (Jenkins agents, GitLab runners) on developer systems that poll cloud-hosted build infrastructure at regular intervals
- Backup agents (Veeam, Acronis, Commvault) performing scheduled incremental syncs to cloud storage endpoints on VPS infrastructure
Other platforms for T1583.003
Testing Methodology
Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Simulate C2 Beacon via PowerShell HTTP Check-in to VPS-like Endpoint
Expected signal: Sysmon Event ID 1: Process Create with Image=powershell.exe and CommandLine containing '-WindowStyle Hidden' and 'Invoke-WebRequest'. Sysmon Event ID 3: 15 network connections from powershell.exe to 127.0.0.1:8443 at approximately 5-second intervals. PowerShell ScriptBlock Log Event ID 4104 with the full script body.
- Test 2Simulate VPS Payload Download via LOLBin (certutil)
Expected signal: Sysmon Event ID 1: Process Create with Image=certutil.exe and CommandLine containing '-urlcache' and '-f'. Sysmon Event ID 3: Network Connection from certutil.exe to 127.0.0.1:8080. Sysmon Event ID 11: File Create attempt for %TEMP%\df00tech-vps-test.exe (may not succeed if no listener). Security Event ID 4688 (if command line auditing enabled).
- Test 3Simulate VPS-based Reconnaissance Inbound Scan Detection (nmap from localhost)
Expected signal: Linux auditd: syscall execve for nmap with full argument list. Syslog: nmap process execution. Network: TCP SYN packets to localhost ports 22, 80, 443, 3389, 8080, 8443. If monitoring inbound scan patterns on perimeter, this generates SYN packets with no corresponding application connection.
- Test 4Simulate Azure AD Authentication from VPS IP Range via PowerShell Graph API Call
Expected signal: Sysmon Event ID 1: Process Create with Image=powershell.exe. Sysmon Event ID 3: Network Connection from powershell.exe to login.microsoftonline.com:443. Sysmon Event ID 22 (DNS Query): DNS resolution of login.microsoftonline.com. PowerShell ScriptBlock Log Event ID 4104.
References (12)
- https://attack.mitre.org/techniques/T1583/003/
- https://documents.trendmicro.com/assets/wp/wp-criminal-hideouts-for-lease.pdf
- https://michaelkoczwara.medium.com/cobalt-strike-c2-hunting-with-shodan-c448d501a6e2
- https://threatconnect.com/blog/infrastructure-research-hunting/
- https://cloud.google.com/blog/topics/threat-intelligence/scandalous-external-detection-using-network-scan-data-and-automation/
- https://www.cisa.gov/news-events/cybersecurity-advisories/aa24-249a
- https://www.microsoft.com/en-us/security/blog/2022/03/22/dev-0537-criminal-actor-targeting-organizations-for-data-exfiltration-and-destruction/
- https://unit42.paloaltonetworks.com/unit-42-gamaredon-group-russia-linked/
- https://www.sentinelone.com/labs/winter-vivern-all-you-need-is-one-side-loading-and-a-good-lure/
- https://www.ic3.gov/Media/News/2022/220211.pdf
- https://learn.microsoft.com/en-us/azure/sentinel/understand-threat-intelligence
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-devicenetworkevents-table
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