Exfiltration Over Alternative Protocol: Exfiltration Over Unencrypted Non-C2 Protocol T1048.003
Tactic: Exfiltration
Adversaries may steal data by exfiltrating it over an un-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.
Events covered
9 catalog events are tagged with this technique by at least one rule.
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Sysmon | Event ID 3 | Network connection |
| Sysmon | Event ID 22 | DNSEvent (DNS query) |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| ESF | exec | Process Execution (Notify) |
| Linux-Auditd | Event ID 1309 | EXECVE |
| PowerShell | Event ID 4103 | Payload Context: ContextInfo User Data: UserData. |
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
| Sysmon-for-Linux | Event ID 1 | Process Create |
Authoring guide
Patterns shared across the 31 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.
Fields filtered most (44 distinct)
The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.
Top indicator values (182 distinct)
Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique. Click a value to expand the rules under this technique that use it.
Exclusions (55 distinct)
Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths. Click a value to expand the rules under this technique that exclude it.
Rules under this technique
Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.
Sigma 9 rules
- Data Exfiltration with Wget
- Potential Data Exfiltration Over SMTP Via Send-MailMessage Cmdlet
- PowerShell ICMP Exfiltration
- Python WebServer Execution - Linux
- Suspicious DNS Query with B64 Encoded String
- Suspicious Outbound SMTP Connections
- Suspicious WebDav Client Execution Via Rundll32.EXE
- WebDav Client Execution Via Rundll32.EXE
- WebDav Put Request
Elastic 3 rules
- File Transfer or Listener Established via Netcat
- Netcat File Transfer or Listener Detected via Defend for Containers
- Potential Data Exfiltration Through Curl
Splunk 19 rules
- BITSadmin Execution (PowerShell)
- BITSadmin Execution (Sysmon)
- BITSadmin Execution (Windows Event Log)
- Cisco ASA - Device File Copy to Remote Location
- Cisco Secure Firewall - Potential Data Exfiltration
- DNS Query Length With High Standard Deviation
- Gsuite Outbound Email With Attachment To External Domain
- Multiple Archive Files Http Post Traffic
- Plain HTTP POST Exfiltrated Data
- Potential CVE-2023-23397 (EDR)
- Potential CVE-2023-23397 (Sysmon)
- Potential CVE-2023-23397 (Windows Event Log)
- Protocol or Port Mismatch
- Rclone Execution (PowerShell)
- Rclone Execution (Sysmon)
- Rclone Execution (Windows Event Log)
- Windows Rundll32 WebDAV Request
- Windows Rundll32 WebDav With Network Connection
- WinSCP Execution (Windows Event Log)