Rule Library

Sigma Rules

3,132 rules found for "sigma"

3,731Total
3,132Detection
457Emerging
139Hunting
Detectionmediumtest

Potential PetitPotam Attack Via EFS RPC Calls

Detects usage of the windows RPC library Encrypting File System Remote Protocol (MS-EFSRPC). Variations of this RPC are used within the attack refereed to as PetitPotam. The usage of this RPC function should be rare if ever used at all. Thus usage of this function is uncommon enough that any usage of this RPC function should warrant further investigation to determine if it is legitimate. View surrounding logs (within a few minutes before and after) from the Source IP to. Logs from from the Source IP would include dce_rpc, smb_mapping, smb_files, rdp, ntlm, kerberos, etc..'

Zeek (Bro)dce_rpc
@neu5ron+2Tue Aug 17network
Detectionmediumtest

SMB Spoolss Name Piped Usage

Detects the use of the spoolss named pipe over SMB. This can be used to trigger the authentication via NTLM of any machine that has the spoolservice enabled.

Zeek (Bro)smb_files
OTR (Open Threat Research)Wed Nov 28network
Detectionhightest

Default Cobalt Strike Certificate

Detects the presence of default Cobalt Strike certificate in the HTTPS traffic

Zeek (Bro)x509
Bhabesh RajWed Jun 23network
Detectionhighexperimental

Suspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing - Network

Detects DNS queries containing patterns associated with Kerberos coercion attacks via DNS object spoofing. The pattern "1UWhRCAAAAA..BAAAA" is a base64-encoded signature that corresponds to a marshaled CREDENTIAL_TARGET_INFORMATION structure. Attackers can use this technique to coerce authentication from victim systems to attacker-controlled hosts. It is one of the strong indicators of a Kerberos coercion attack, where adversaries manipulate DNS records to spoof Service Principal Names (SPNs) and redirect authentication requests like CVE-2025-33073.

Zeek (Bro)dns
Swachchhanda Shrawan Poudel (Nextron Systems)Fri Jun 20network
Detectionlowtest

DNS Events Related To Mining Pools

Identifies clients that may be performing DNS lookups associated with common currency mining pools.

Zeek (Bro)dns
Saw Winn Naung+1Thu Aug 19network
Detectionlowtest

New Kind of Network (NKN) Detection

NKN is a networking service using blockchain technology to support a decentralized network of peers. While there are legitimate uses for it, it can also be used as a C2 channel. This rule looks for a DNS request to the ma>

Zeek (Bro)dns
Michael PorteraThu Apr 21network
Detectionmediumtest

Suspicious DNS Z Flag Bit Set

The DNS Z flag is bit within the DNS protocol header that is, per the IETF design, meant to be used reserved (unused). Although recently it has been used in DNSSec, the value being set to anything other than 0 should be rare. Otherwise if it is set to non 0 and DNSSec is being used, then excluding the legitimate domains is low effort and high reward. Determine if multiple of these files were accessed in a short period of time to further enhance the possibility of seeing if this was a one off or the possibility of larger sensitive file gathering. This Sigma query is designed to accompany the Corelight Threat Hunting Guide, which can be found here: https://www3.corelight.com/corelights-introductory-guide-to-threat-hunting-with-zeek-bro-logs'

Zeek (Bro)dns
@neu5ron+2Tue May 04network
Detectionmediumtest

DNS TOR Proxies

Identifies IPs performing DNS lookups associated with common Tor proxies.

Zeek (Bro)dns
Saw Winn Naung+1Sun Aug 15network
Detectionmediumtest

Executable from Webdav

Detects executable access via webdav6. Can be seen in APT 29 such as from the emulated APT 29 hackathon https://github.com/OTRF/detection-hackathon-apt29/

Zeek (Bro)http
SOC Prime+1Fri May 01network
Detectionmediumexperimental

HTTP Request to Low Reputation TLD or Suspicious File Extension

Detects HTTP requests to low reputation TLDs (e.g. .xyz, .top, .ru) or ending in suspicious file extensions (.exe, .dll, .hta), which may indicate malicious activity.

Zeek (Bro)http
@signalblur+1Wed Feb 26network
Detectionlowtest

WebDav Put Request

A General detection for WebDav user-agent being used to PUT files on a WebDav network share. This could be an indicator of exfiltration.

Zeek (Bro)http
Roberto Rodriguez (Cyb3rWard0g)+1Sat May 02network
Detectionhightest

Publicly Accessible RDP Service

Detects connections from routable IPs to an RDP listener. Which is indicative of a publicly-accessible RDP service.

Zeek (Bro)rdp
Josh BrowerSat Aug 22network
Detectionmediumtest

Remote Task Creation via ATSVC Named Pipe - Zeek

Detects remote task creation via at.exe or API interacting with ATSVC namedpipe

Zeek (Bro)smb_files
Samir BousseadenFri Apr 03network
Detectionhightest

Possible Impacket SecretDump Remote Activity - Zeek

Detect AD credential dumping using impacket secretdump HKTL. Based on the SIGMA rules/windows/builtin/win_impacket_secretdump.yml

Zeek (Bro)smb_files
Samir BousseadenThu Mar 19network
Detectionhightest

First Time Seen Remote Named Pipe - Zeek

This detection excludes known namped pipes accessible remotely and notify on newly observed ones, may help to detect lateral movement and remote exec using named pipes

Zeek (Bro)smb_files
Samir Bousseaden+1Thu Apr 02network
Detectionhightest

Suspicious PsExec Execution - Zeek

detects execution of psexec or paexec with renamed service name, this rule helps to filter out the noise if psexec is used for legit purposes or if attacker uses a different psexec client other than sysinternal one

Zeek (Bro)smb_files
Samir Bousseaden+1Thu Apr 02network
Detectionmediumtest

Suspicious Access to Sensitive File Extensions - Zeek

Detects known sensitive file extensions via Zeek

Zeek (Bro)smb_files
Samir BousseadenThu Apr 02network
Detectionmediumtest

Transferring Files with Credential Data via Network Shares - Zeek

Transferring files with well-known filenames (sensitive files with credential data) using network shares

Zeek (Bro)smb_files
@neu5ron+2Thu Apr 02network
Detectionmediumtest

Kerberos Network Traffic RC4 Ticket Encryption

Detects kerberos TGS request using RC4 encryption which may be indicative of kerberoasting

Zeek (Bro)kerberos
sigmaWed Feb 12network
Detectionhightest

Apache Segmentation Fault

Detects a segmentation fault error message caused by a crashing apache worker process

apache
Florian Roth (Nextron Systems)Tue Feb 28web
Detectionmediumtest

Apache Threading Error

Detects an issue in apache logs that reports threading related errors

apache
Florian Roth (Nextron Systems)Tue Jan 22web
Detectionhightest

Nginx Core Dump

Detects a core dump of a crashing Nginx worker process, which could be a signal of a serious problem or exploitation attempts.

nginx
Florian Roth (Nextron Systems)Mon May 31web
Detectionhightest

Windows WebDAV User Agent

Detects WebDav DownloadCradle

Proxy Log
Florian Roth (Nextron Systems)Fri Apr 06web
Detectionmediumtest

Download from Suspicious Dyndns Hosts

Detects download of certain file types from hosts with dynamic DNS names (selected list)

Proxy Log
Florian Roth (Nextron Systems)Wed Nov 08web
Detectionlowtest

Download From Suspicious TLD - Blacklist

Detects download of certain file types from hosts in suspicious TLDs

Proxy Log
Florian Roth (Nextron Systems)Tue Nov 07web
Detectionlowtest

Download From Suspicious TLD - Whitelist

Detects executable downloads from suspicious remote systems

Proxy Log
Florian Roth (Nextron Systems)Mon Mar 13web
Detectionmediumtest

F5 BIG-IP iControl Rest API Command Execution - Proxy

Detects POST requests to the F5 BIG-IP iControl Rest API "bash" endpoint, which allows the execution of commands on the BIG-IP

Proxy Log
Nasreddine Bencherchali (Nextron Systems)+1Wed Nov 08web
Detectionmediumexperimental

Potential Hello-World Scraper Botnet Activity

Detects network traffic potentially associated with a scraper botnet variant that uses the "Hello-World/1.0" user-agent string.

Proxy Log
Joseph A. M.Sat Aug 02web
Detectioncriticaltest

HackTool - BabyShark Agent Default URL Pattern

Detects Baby Shark C2 Framework default communication patterns

Proxy Log
Florian Roth (Nextron Systems)Wed Jun 09web
Detectionhightest

HackTool - CobaltStrike Malleable Profile Patterns - Proxy

Detects cobalt strike malleable profiles patterns (URI, User-Agents, Methods).

Proxy Log
Markus Neis+1Thu Feb 15web
Detectionhightest

HackTool - Empire UserAgent URI Combo

Detects user agent and URI paths used by empire agents

Proxy Log
Florian Roth (Nextron Systems)Mon Jul 13web
Detectionmediumtest

PUA - Advanced IP/Port Scanner Update Check

Detect the update check performed by Advanced IP/Port Scanner utilities.

Proxy Log
Axel OlssonSun Aug 14web
Detectioncriticaltest

PwnDrp Access

Detects downloads from PwnDrp web servers developed for red team testing and most likely also used for criminal activity

Proxy Log
Florian Roth (Nextron Systems)Wed Apr 15web
Detectionhightest

Raw Paste Service Access

Detects direct access to raw pastes in different paste services often used by malware in their second stages to download malicious code in encrypted or encoded form

Proxy Log
Florian Roth (Nextron Systems)Thu Dec 05web
Detectionhightest

Flash Player Update from Suspicious Location

Detects a flashplayer update from an unofficial location

Proxy Log
Florian Roth (Nextron Systems)Wed Oct 25web
Detectionlowtest

Suspicious Network Communication With IPFS

Detects connections to interplanetary file system (IPFS) containing a user's email address which mirrors behaviours observed in recent phishing campaigns leveraging IPFS to host credential harvesting webpages.

Proxy Log
Gavin KnappThu Mar 16web
Detectionmediumtest

Telegram API Access

Detects suspicious requests to Telegram API without the usual Telegram User-Agent

Proxy Log
Florian Roth (Nextron Systems)Tue Jun 05web
Detectionhightest

APT User Agent

Detects suspicious user agent strings used in APT malware in proxy logs

Proxy Log
Florian Roth (Nextron Systems)+1Tue Nov 12web
Detectionmediumtest

Suspicious Base64 Encoded User-Agent

Detects suspicious encoded User-Agent strings, as seen used by some malware.

Proxy Log
Nasreddine Bencherchali (Nextron Systems)Thu May 04web
Detectionhightest

Bitsadmin to Uncommon IP Server Address

Detects Bitsadmin connections to IP addresses instead of FQDN names

Proxy Log
Florian Roth (Nextron Systems)Fri Jun 10web
Detectionhightest

Bitsadmin to Uncommon TLD

Detects Bitsadmin connections to domains with uncommon TLDs

Proxy Log
Florian Roth (Nextron Systems)+1Thu Mar 07web
Detectionhightest

Crypto Miner User Agent

Detects suspicious user agent strings used by crypto miners in proxy logs

Proxy Log
Florian Roth (Nextron Systems)Mon Oct 21web
Detectionmediumtest

HTTP Request With Empty User Agent

Detects a potentially suspicious empty user agent strings in proxy log. Could potentially indicate an uncommon request method.

Proxy Log
Florian Roth (Nextron Systems)Sat Jul 08web
Detectionhightest

Exploit Framework User Agent

Detects suspicious user agent strings used by exploit / pentest frameworks like Metasploit in proxy logs

Proxy Log
Florian Roth (Nextron Systems)Sat Jul 08web
Detectionhightest

Hack Tool User Agent

Detects suspicious user agent strings user by hack tools in proxy logs

Proxy Log
Florian Roth (Nextron Systems)Sat Jul 08web
Detectionhightest

Malware User Agent

Detects suspicious user agent strings used by malware in proxy logs

Proxy Log
Florian Roth (Nextron Systems)+2Sat Jul 08web
Detectionmediumtest

Windows PowerShell User Agent

Detects Windows PowerShell Web Access

Proxy Log
Florian Roth (Nextron Systems)Mon Mar 13web
Detectionmediumtest

Rclone Activity via Proxy

Detects the use of rclone, a command-line program to manage files on cloud storage, via its default user-agent string

Proxy Log
Janantha MarasingheTue Oct 18web