Sigma detection rules, expert-reviewed

Linux Remote System Discovery via arp and ping Process Execution

Flags Linux arp or ping commands with LAN/loopback/link-local IP range arguments consistent with remote host discovery.

macOS Process Network Service Scanning via nc or nmap/telnet

Flags macOS executions of nc/netcat, nmap, or telnet consistent with local or remote service enumeration.

Linux: Process Execution of Network Scanning and Recon Tools

Flags Linux process executions of common network scanning/recon utilities based on executable name (and netcat listen flag filtering).

Linux auditd: Network service enumeration via telnet, nmap, or netcat

Alerts when telnet/nmap/netcat-style binaries are executed on Linux via auditd, consistent with service discovery scanning.

Windows Event Log Detects Volume Shadow Copy Mounts (HarddiskVolumeShadowCopy, EventID 98)

Alerts when NTFS logs indicate a VSS (HarddiskVolumeShadowCopy) mount using EventID 98.

macOS Gatekeeper bypass attempt using xattr to remove com.apple.quarantine

Flags macOS xattr usage that deletes the com.apple.quarantine extended attribute, consistent with a Gatekeeper bypass attempt.

macOS Base64 Utility Decoding Command Activity

Flags macOS base64 decoding by detecting /usr/bin/base64 runs with the -d argument.

Linux System Network Connections Discovery via who, w, last, lsof, or netstat

Identifies Linux discovery activity using who/w/last/lsof/netstat for enumerating network connections and system state.

Linux process discovery via grep/egrep searching for security software strings

Alerts when grep/egrep on Linux searches command lines for indicators of security/monitoring tools.

Linux Base64 Utility Decoding with -d/--decode in Process Creation

Identifies Linux base64 decoding activity using base64 with the -d/--decode flag.

Windows RunOnce Execution via runonce.exe With AlternateShellStartup and /r

Alerts on runonce.exe executing with /AlternateShellStartup and /r, consistent with configured RunOnce persistence behavior.

macOS split Command Used to Divide Files into Parts

Flags macOS process execution of split, indicating file splitting activity that may support staging or exfiltration.

Linux split Command Used to Divide Files for Possible Exfiltration

Identifies use of the Linux split command to break files into parts, potentially for staging or exfiltration.

macOS Startup Item Plist Created in StartupItems Folders

Alerts on creation of startup item .plist files in macOS StartupItems directories, potential boot persistence setup.

Windows te.exe Execution of Test Components (TAEF) via Process Creation

Alerts on process activity involving te.exe, which may indicate TAEF-based execution of malicious test components.