Detections

Explore public detection logic contributed by the community across SIEM and rule languages.

881 detections

This rule detects Telnet access attempts to network devices within the home network. It specifically looks for TCP traffic destined for port 23 (the standard Telnet port) and triggers an alert if three such connections from the same source IP are observed within a 60-second window. This activity is flagged as a 'possible compromise' due to Telnet's insecure nature and its common use in initial access or resource development by adversaries.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
104
This rule detects a high volume (5 or more within an hour) of process creation events where the command line contains keywords associated with remote access protocols like DCOM, WMI, or RPC. This could indicate an adversary utilizing these protocols for lateral movement or remote execution.
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Ankit Mehta@Secvyn
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Detections.ai Community
5 months ago
002
This rule detects potential SSH agent forwarding abuse, which can be used for lateral movement within a network. It specifically looks for a byte sequence ('|00 00 00 1c 0b|') within TCP traffic on port 22 (SSH) flowing to the server, indicating an established connection. This byte sequence is characteristic of SSH agent forwarding requests.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
004
This rule detects an attempt to establish a VNC (Virtual Network Computing) connection from an external source to a host within the protected network. It specifically looks for TCP SYN packets (initial connection attempt) destined for common VNC ports (5900-5910) on the home network. This could indicate an attacker attempting to gain remote access to internal systems.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
004
This rule detects attempts to establish a TCP connection to port 5985 on the home network, which is commonly used for WinRM (Windows Remote Management) over HTTP. The rule is configured to alert if three such connection attempts are made from the same source within a 60-second window, indicating potential lateral movement activity using WinRM.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
004
This rule detects potential lateral movement activity by identifying a single user account attempting to log on to five or more distinct computers with at least ten logon attempts within a five-minute window. It specifically looks for successful logons (EventID 4624) with network, remote interactive, or remote desktop logon types (LogonType 3, 9, 10) and excludes machine accounts (TargetUserName not ending with '$'). This pattern can indicate an adversary attempting to spread across the network using compromised credentials.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
102
Detects named pipe activity with remote access enabled, initiated by JsonVMAccessExtension.exe running as SYSTEM. This may indicate abuse of the Azure VM Access Extension for unauthorized remote access.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
002
This rule detects attempts to perform lateral movement using the MMC20 COM object via DCOM. It specifically looks for TCP traffic destined for port 135 (typically used by DCOM) containing the string "MMC20.Application" in a case-insensitive manner. This indicates an attempt to instantiate the MMC20.Application COM object, which can be abused for remote code execution and lateral movement.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects HTTP requests to URIs containing keywords associated with common IT management platforms (ConnectWise, Kaseya, SolarWinds, Datto, N-central). It specifically looks for established HTTP traffic flowing to the server. A threshold of 5 occurrences within 60 seconds from the same source IP is set to trigger an alert, indicating a potential remote access session or activity related to these platforms.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects RDP (Remote Desktop Protocol) sessions initiated towards the HOME_NET on port 3389. It specifically looks for the RDP connection initiation sequence (content:"|03 00|" with depth:2) and uses a threshold to detect multiple connections from the same source within a 5-minute window, which could indicate activity from a Managed Service Provider or other remote access scenarios.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
003
This rule detects potential session hijacking or token replay attacks against Okta by identifying a single Okta session (externalSessionId) being used from multiple distinct origins. It specifically looks for divergence in client country, device hash (dtHash), or operating system within the same session, rather than just multiple IP addresses, to reduce false positives. This behavior is indicative of a stolen post-MFA cookie being replayed by an attacker.
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Lacey Cochrane@NullVectorX
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XQL Threat Forge
5 months ago
12018
This rule detects potential RDP session hijacking attempts by looking for the string "tscon" within TCP traffic destined for port 3389 (RDP). The 'tscon' command can be used to connect to or take control of another user's RDP session.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
002
Detects named pipe activity with remote access enabled, initiated by JsonVMAccessExtension.exe running as SYSTEM. This may indicate abuse of the Azure VM Access Extension for unauthorized remote access.
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Ankit Mehta@Secvyn
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Detections.ai Community
5 months ago
103
This rule detects HTTP network connections to TeamViewer domains, specifically 'teamviewer.com' or 'router.teamviewer.com'. It triggers an alert if five such connections are observed from the same source IP within a 60-second window. This behavior is indicative of TeamViewer being used for persistent command and control (C2) activities, often associated with trojan activity.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
001
This rule detects a multi-stage attack chain associated with the Nimbus RAT, starting with a suspicious Microsoft Teams message (vishing) from an external sender using throwaway domains (e.g., .onmicrosoft.com, .top). This initial communication is then correlated with subsequent reconnaissance activities performed via Quick Assist, where QuickAssist.exe spawns cmd.exe to execute commands like 'net time', '/domain', 'whoami', 'ipconfig', or 'systeminfo' on the victim's device within a two-hour window. The rule aims to identify the internal victim and the external sender involved in this coordinated attack.
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Bryant Smith@flowstate
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Detections.ai Community
5 months ago
6023
This rule detects attempts to establish a WinRM HTTPS connection (port 5986) to a host on the home network. It specifically looks for TCP SYN packets (flags:S) and triggers if three such connection attempts are made from the same source within 60 seconds. This pattern can indicate lateral movement activity using WinRM over HTTPS.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
002
Monitors for the execution of Windows 365 native clients. UNC3753 abuses legitimate VDI clients on compromised personal devices to bypass initial corporate perimeters and access sensitive network segments.
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Duo Tech@duotech
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Detections.ai Community
5 months ago
303
This rule detects suspicious activity involving Azure AD device registration followed by a sign-in from the same user and IP address, particularly when the user agent strings are indicative of non-standard clients (e.g., 'node', 'axios', 'undici', 'node-fetch'). This pattern can indicate an adversary attempting to establish persistence or bypass multi-factor authentication by registering a new device and then immediately using it for access.
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Frederico Canhoto@nullwhire
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Detections.ai Community
5 months ago
150100
This rule detects VNC (Virtual Network Computing) remote access sessions initiated from any source IP address to any IP address within the local network ($HOME_NET) on port 5900. It specifically looks for the 'RFB 00' string within the first 7 bytes of the TCP payload, which is characteristic of the VNC protocol handshake. A threshold is applied to trigger an alert if 3 such connections are observed from the same source IP within a 60-second window, indicating potential repeated or sustained VNC activity.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
001
This Suricata rule detects potential internal RDP session hijack attempts. It triggers an alert when there are three or more established TCP connections to port 3389 (RDP) on the home network, originating from within the home network, within a 30-second window, tracked by the destination IP address. This pattern could indicate an attacker attempting to take over an existing RDP session or rapidly establish multiple RDP connections internally.
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Darshan Thummar@Mighty
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Detections.ai Community
5 months ago
001
This rule detects a high volume (5 or more within an hour) of process creation events where the command line contains keywords associated with remote access protocols like DCOM, WMI, or RPC. This could indicate an adversary utilizing these protocols for lateral movement or remote execution.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
5 months ago
000
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