Cross-source coverage

T1102.003 / ATT&CK

Web Service: One-Way Communication

2 rules across 1 source.

2 atomic-IOC hidden · include

From MITRE ATT&CK 19.2

Adversaries may use an existing, legitimate external Web service as a means for sending commands to a compromised system without receiving return output over the Web service channel. Compromised systems may leverage popular websites and social media to host command and control (C2) instructions. Those infected systems may opt to send the output from those commands back over a different C2 channel, including to another distinct Web service. Alternatively, compromised systems may return no output at all in cases where adversaries want to send instructions to systems and do not want a response.

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. Using common services, such as those offered by Google or Twitter, makes it easier for adversaries to hide in expected noise. Web service providers commonly use SSL/TLS encryption, giving adversaries an added level of protection.

Platforms
Linux · macOS · Windows · ESXi
Telemetry
WinEventLog:Sysmonetw:Microsoft-Windows-WinINetauditd:SYSCALLiptables:LOGmacos:unifiedlogmacos:endpointsecurityesxi:hostd

How MITRE says to detect it DET0581

Detect One-Way Web Service Command Channels

Windows Analytic 1599

Suspicious process initiating outbound connections to web services without corresponding response or return traffic, indicative of one-way command channels.

  • WinEventLog:Sysmon EventCode=3, 22
  • etw:Microsoft-Windows-WinINet WinINet API telemetry

Linux Analytic 1600

Curl, wget, or custom HTTP clients initiated by uncommon user accounts or cron jobs to popular web services, with no observed response parsing logic.

  • auditd:SYSCALL execve
  • iptables:LOG OUTBOUND

macOS Analytic 1601

Process using URLSession or similar API to fetch from web services without any response handling, indicative of one-way C2 channels.

  • macos:unifiedlog process, network
  • macos:endpointsecurity exec events

ESXi Analytic 1602

ESXi shell or scheduled tasks initiating outbound HTTPS to known public services without inbound return or loggable response, used to fetch instructions.

  • esxi:hostd CLI network calls

elastic/detection-rules

2 rules
Detection Severity Format
Suspicious File Downloaded from Google Drive Medium Elastic TOML
AWS SNS Rare Protocol Subscription by User Low Elastic TOML

Detection rules belong to the projects that publish them and remain under their own licenses. This site indexes and links to them; it claims no rights in them.