Remote Services: SSH T1021.004
Tactic: Lateral Movement
Adversaries may use Valid Accounts to log into remote machines using Secure Shell (SSH). The adversary may then perform actions as the logged-on user.
Events covered
6 catalog events are tagged with this technique by at least one rule.
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| PowerShell | Event ID 4103 | Payload Context: ContextInfo User Data: UserData. |
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
| OpenSSH | Event ID 4 | process: payload. |
| PowerShell | Event ID 800 | Event ID 800 |
Authoring guide
Patterns shared across the 41 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 (47 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 (256 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 (155 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 10 rules
- Bitbucket Global SSH Settings Changed
- Bitbucket User Login Failure Via SSH
- macOS File Transfer Tool Execution
- macOS SSH Connection Detection
- OpenEDR Spawning Command Shell
- OpenSSH native server feature installation
- OpenSSH Server Listening On Socket
- OpenSSH server listening on socket
- OpenSSH service activation on Windows
- Port Forwarding Activity Via SSH.EXE
Elastic 19 rules
- AWS EC2 CreateKeyPair by New Principal from Non-Cloud AS Organization
- AWS EC2 Instance Connect SSH Public Key Uploaded
- Linux SSH X11 Forwarding
- Network Connection Initiated by Suspicious SSHD Child Process
- Potential Execution via SSH Backdoor
- Potential Internal Linux SSH Brute Force Detected
- Potential Remote Desktop Tunneling Detected
- Potential THC Tool Downloaded
- Remote File Creation in World Writeable Directory
- Remote SSH Login Enabled via systemsetup Command
- Renaming of OpenSSH Binaries
- SSH Authorized Key File Activity Detected via Defend for Containers
- SSH Authorized Keys File Activity
- SSH Key Generated via ssh-keygen
- Successful SSH Authentication from Unusual IP Address
- Successful SSH Authentication from Unusual SSH Public Key
- Successful SSH Authentication from Unusual User
- Unusual Remote File Creation
- Unusual SSHD Child Process
Splunk 9 rules
- Cisco IOS XE Remote Access Probe Burst
- Cisco Privileged Account Creation with HTTP Command Execution
- Cisco Privileged Account Creation with Suspicious SSH Activity
- Cisco Secure Firewall - SSH Connection to Non-Standard Port
- Cisco Secure Firewall - SSH Connection to sshd_operns
- ESXi SSH Enabled
- Linux SSH Remote Services Script Execute
- Windows Protocol Tunneling with Plink
- Windows PuTTY Suite Utility Execution