Analytics Story: Salt Typhoon

Date: 2025-03-19 ID: 7df800b1-af23-4f65-ac36-abe87374ee72 Author: Teoderick Contreras, Splunk Product: Splunk Enterprise Security

Description

Leverage searches that allow you to detect and investigate unusual activities that might relate to Salt Typhoon, a sophisticated threat actor targeting various sectors with espionage-focused campaigns. Monitor for indicators such as spear-phishing emails, unauthorized access attempts, and lateral movement within your network. Investigate anomalous data exfiltration patterns and command-and-control (C2) traffic consistent with known tactics, techniques, and procedures (TTPs) of this group. Combining threat intelligence with advanced monitoring tools helps identify potential Salt Typhoon activity early, enabling swift response to mitigate risks effectively.

Why it matters

Salt Typhoon is a highly capable threat actor known for conducting targeted espionage campaigns against diverse sectors, including government, technology, and critical infrastructure. This group leverages sophisticated tactics such as spear-phishing, credential theft, and exploiting software vulnerabilities to gain initial access. Once inside a network, Salt Typhoon demonstrates expertise in lateral movement, privilege escalation, and covert data exfiltration. Their use of custom malware and command-and-control (C2) infrastructures highlights their adaptability. Detecting their activity requires robust threat intelligence and proactive monitoring of unusual behaviors and network anomalies.

Correlation Search

Cisco Privileged Account Creation with Suspicious SSH Activity

 1| tstats `security_content_summariesonly`
 2  min(_time) as firstTime
 3  max(_time) as lastTime
 4
 5  sum(All_Risk.calculated_risk_score) as risk_score
 6  count(All_Risk.calculated_risk_score) as risk_event_count
 7
 8  values(All_Risk.annotations.mitre_attack.mitre_tactic_id) as annotations.mitre_attack.mitre_tactic_id
 9  dc(All_Risk.annotations.mitre_attack.mitre_tactic_id) as mitre_tactic_id_count
10
11  values(All_Risk.annotations.mitre_attack.mitre_technique_id) as annotations.mitre_attack.mitre_technique_id
12  dc(All_Risk.annotations.mitre_attack.mitre_technique_id) as mitre_technique_id_count
13
14  values(All_Risk.tag) as tag
15  values(source) as source
16  dc(source) as source_count
17  
18  values(contributing_events_search)
19
20  values(All_Risk.threat_object)
21
22  from datamodel=Risk.All_Risk where
23
24  source IN (
25    "*Cisco IOS Suspicious Privileged Account Creation*",
26    "*Cisco Secure Firewall - SSH Connection to sshd_operns*",
27    "*Cisco Secure Firewall - SSH Connection to Non-Standard Port*"
28  )
29  by All_Risk.normalized_risk_object
30| `drop_dm_object_name(All_Risk)`
31| eval has_account_creation=if(
32                                match(source, "Cisco IOS Suspicious Privileged Account Creation"),
33                                1, 0
34                              )
35| eval has_ssh_detection=if(
36                              match(source, "SSH Connection to sshd_operns")
37                              OR
38                              match(source, "SSH Connection to Non-Standard Port"),
39                              1, 0
40                            )
41| where has_account_creation=1
42        AND
43        has_ssh_detection=1
44| `security_content_ctime(firstTime)`
45| `security_content_ctime(lastTime)`
46| `cisco_privileged_account_creation_with_suspicious_ssh_activity_filter`

Detections

Name ▲▼	Technique ▲▼	Type ▲▼
Detect Rare Executables	User Execution	Anomaly
Detect Renamed PSExec	Service Execution	Hunting
Detect Renamed WinRAR	Archive via Utility	Hunting
Executables Or Script Creation In Suspicious Path	Masquerading	Anomaly
Executables Or Script Creation In Temp Path	Masquerading	Anomaly
Linux Auditd File Permission Modification Via Chmod	Linux and Mac File and Directory Permissions Modification	Anomaly
Linux Auditd Nopasswd Entry In Sudoers File	Sudo and Sudo Caching	Anomaly
Linux Auditd Possible Access To Credential Files	/etc/passwd and /etc/shadow	Anomaly
Linux Auditd Possible Access To Sudoers File	Sudo and Sudo Caching	Anomaly
Linux Auditd Preload Hijack Library Calls	Dynamic Linker Hijacking	TTP
Linux Common Process For Elevation Control	Setuid and Setgid	Hunting
Linux NOPASSWD Entry In Sudoers File	Sudo and Sudo Caching	Anomaly
Linux Possible Access To Credential Files	/etc/passwd and /etc/shadow	Anomaly
Linux Possible Access To Sudoers File	Sudo and Sudo Caching	Anomaly
Linux Preload Hijack Library Calls	Dynamic Linker Hijacking	TTP
Linux Sudoers Tmp File Creation	Sudo and Sudo Caching	Anomaly
Malicious PowerShell Process - Execution Policy Bypass	PowerShell	Anomaly
Non Chrome Process Accessing Chrome Default Dir	Credentials from Web Browsers	Anomaly
Non Firefox Process Access Firefox Profile Dir	Credentials from Web Browsers	Anomaly
PowerShell 4104 Hunting	PowerShell	Hunting
Registry Keys Used For Persistence	Registry Run Keys / Startup Folder	TTP
Remote Process Instantiation via WMI	Windows Management Instrumentation	TTP
Scheduled Task Deleted Or Created via CMD	Scheduled Task	TTP
Suspicious Regsvr32 Register Suspicious Path	Regsvr32	TTP
Suspicious Scheduled Task from Public Directory	Scheduled Task	Anomaly
Windows Access Token Manipulation SeDebugPrivilege	Create Process with Token	Anomaly
Windows Anonymous Pipe Activity	Inter-Process Communication	Hunting
Windows Archive Collected Data via Rar	Archive via Utility	Anomaly
Windows Credential Access From Browser Password Store	Query Registry	Anomaly
Windows Credentials from Password Stores Chrome LocalState Access	Query Registry	Anomaly
Windows Credentials from Password Stores Chrome Login Data Access	Query Registry	Anomaly
Windows Curl Download to Suspicious Path	Ingress Tool Transfer	TTP
Windows Process Execution From ProgramData	Match Legitimate Resource Name or Location	Anomaly
Windows Query Registry Browser List Application	Query Registry	Anomaly
Windows Replication Through Removable Media	Replication Through Removable Media	TTP
Windows Service Created with Suspicious Service Path	Service Execution	TTP
Windows Service Creation on Remote Endpoint	Windows Service	TTP
Windows Service Creation Using Registry Entry	Services Registry Permissions Weakness	Anomaly
Windows SnappyBee Create Test Registry	Modify Registry	TTP
Windows Suspicious Process File Path	Create or Modify System Process, Match Legitimate Resource Name or Location	TTP
Windows Unsigned DLL Side-Loading	DLL	Anomaly
Windows Unsigned DLL Side-Loading In Same Process Path	DLL	TTP
Windows Unsigned MS DLL Side-Loading	DLL, Boot or Logon Autostart Execution	Anomaly
Windows Unusual SysWOW64 Process Run System32 Executable	Break Process Trees	Anomaly
WinEvent Scheduled Task Created to Spawn Shell	Scheduled Task	TTP
WinEvent Scheduled Task Created Within Public Path	Scheduled Task	TTP
Cisco Secure Firewall - Privileged Command Execution via HTTP	Command and Scripting Interpreter, Web Shell	Anomaly
Cisco Secure Firewall - SSH Connection to Non-Standard Port	SSH	Anomaly
Cisco Secure Firewall - SSH Connection to sshd_operns	SSH	Anomaly

Data Sources

Name ▲▼	Platform ▲▼	Sourcetype ▲▼	Source ▲▼
Cisco Network Visibility Module Flow Data	Network	`cisco:nvm:flowdata`	`not_applicable`
Cisco Secure Firewall Threat Defense Intrusion Event	Other	`cisco:sfw:estreamer`	`not_applicable`
CrowdStrike ProcessRollup2	Other	`crowdstrike:events:sensor`	`crowdstrike`
Linux Auditd Cwd	Linux	`auditd`	`auditd`
Linux Auditd Execve	Linux	`auditd`	`auditd`
Linux Auditd Path	Linux	`auditd`	`auditd`
Linux Auditd Proctitle	Linux	`auditd`	`auditd`
Powershell Script Block Logging 4104	Windows	`XmlWinEventLog`	`XmlWinEventLog:Microsoft-Windows-PowerShell/Operational`
Sysmon EventID 1	Windows	`XmlWinEventLog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon EventID 11	Windows	`XmlWinEventLog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon EventID 13	Windows	`XmlWinEventLog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon EventID 17	Windows	`XmlWinEventLog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon EventID 18	Windows	`XmlWinEventLog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon EventID 7	Windows	`XmlWinEventLog`	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`
Sysmon for Linux EventID 1	Linux	`sysmon:linux`	`Syslog:Linux-Sysmon/Operational`
Sysmon for Linux EventID 11	Linux	`sysmon:linux`	`Syslog:Linux-Sysmon/Operational`
Windows Event Log Security 4663	Windows	`XmlWinEventLog`	`XmlWinEventLog:Security`
Windows Event Log Security 4688	Windows	`XmlWinEventLog`	`XmlWinEventLog:Security`
Windows Event Log Security 4698	Windows	`XmlWinEventLog`	`XmlWinEventLog:Security`
Windows Event Log Security 4703	Windows	`XmlWinEventLog`	`XmlWinEventLog:Security`
Windows Event Log System 7045	Windows	`XmlWinEventLog`	`XmlWinEventLog:System`

References

https://www.trendmicro.com/en_nl/research/24/k/earth-estries.html

Source: GitHub | Version: 1