Cross-source coverage
T1048.002 / ATT&CK
Exfiltration Over Alternative Protocol: Exfiltration Over Asymmetric Encrypted Non-C2 Protocol
6 rules across 2 sources.
From MITRE ATT&CK 19.2
Adversaries may steal data by exfiltrating it over an asymmetrically encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.
Asymmetric encryption algorithms are those that use different keys on each end of the channel. Also known as public-key cryptography, this requires pairs of cryptographic keys that can encrypt/decrypt data from the corresponding key. Each end of the communication channels requires a private key (only in the procession of that entity) and the public key of the other entity. The public keys of each entity are exchanged before encrypted communications begin.
Network protocols that use asymmetric encryption (such as HTTPS/TLS/SSL) often utilize symmetric encryption once keys are exchanged. Adversaries may opt to use these encrypted mechanisms that are baked into a protocol.
- Tactics
- Exfiltration
- Platforms
- ESXi · Linux · macOS · Windows
- Telemetry
-
WinEventLog:SysmonWinEventLog:SecurityNSM:Flowauditd:SYSCALLmacos:osquerymacos:unifiedlogesxi:hostdesxi:vmkernel
How MITRE says to detect it DET0512
Detection of Exfiltration Over Asymmetric Encrypted Non-C2 Protocol
Windows Analytic 1413
Detects non-browser processes that establish encrypted outbound connections (e.g., TLS/SSL) to unfamiliar or atypical destinations for the host/user, following a data staging or compression event.
WinEventLog:SysmonEventCode=3, 22WinEventLog:SysmonEventCode=1WinEventLog:SecurityEventCode=4663, 4670, 4656NSM:Flowssl.log - Certificate Analysis
Linux Analytic 1414
Detects staged file access (e.g., archive or obfuscation), followed by an encrypted outbound connection (TLS/HTTPS) from unusual processes such as curl/wget, Python scripts, or custom binaries.
auditd:SYSCALLexecveauditd:SYSCALLconnectNSM:Flowssl.log, conn.logauditd:SYSCALLopen, read
macOS Analytic 1415
Detects abnormal encrypted network connections (via TLS/HTTPS) initiated by non-browser binaries, particularly after sensitive file access or compression events.
macos:osquerysocket_eventsmacos:osqueryprocess_eventsmacos:unifiedloglog stream - file provider subsystemNSM:Flowssl.log, x509.log
ESXi Analytic 1416
Detects unexpected encrypted outbound connections from management components or guest VMs using TLS, particularly after data volume spikes or script-based orchestration from within guest environments.
esxi:hostdevent streamesxi:vmkernelegress logs
chronicle/detection-rules
4 rules| Detection | Severity | Format |
|---|---|---|
| o365_onedrive_anonymous_file_accessed | Medium | YARA-L |
| o365_onedrive_anonymous_filedownload | Medium | YARA-L |
| o365_onedrive_anonymous_link_accessed | Medium | YARA-L |
| o365_file_download | Low | YARA-L |
socfortress/Wazuh-Rules
2 rules| Detection | Severity | Format |
|---|---|---|
| Data exfiltration attempt using wget --post-file | Medium | Wazuh XML |
| Potential exfiltration over HTTPS using curl to file.io (T1048.002) | Medium | Wazuh XML |