Detections

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

219 detections

Detects the use of the HTTP CONNECT method on non-standard ports (8888, 9999, 4444). The CONNECT method is frequently used by HTTP proxies to establish TCP tunnels; unauthorized use of this method on uncommon ports is a common indicator of protocol tunneling used to bypass network egress filtering or for command and control (C2) communication.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
002
Detects outbound HTTPS traffic on non-standard ports that matches a specific JA3 fingerprint associated with the Sliver command and control framework. This indicates potential beaconing or C2 communication from a compromised host.
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Ankit Mehta@Secvyn
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Detections.ai Community
4 months ago
002
Detects outbound UDP traffic over port 3478 (STUN) initiated by common web browsers. This pattern is commonly used by phishing-as-a-service (PaaS) platforms like Bluekit to perform WebRTC IP leak checks, potentially revealing a victim's real IP address behind a proxy or VPN. The rule excludes common communication platforms like Microsoft Teams, Zoom, and Webex to reduce false positives.
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Ibrahim Saud@tektrix
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Detections.ai Community
4 months ago
108
This rule detects potential command and control (C2) beaconing activity by identifying devices communicating with known suspicious remote IP addresses at regular, repeating intervals. It calculates the time difference between consecutive connections to specific suspicious IPs and identifies devices that establish at least three connections within one-hour bins, adhering to a 1 to 15-minute heartbeat interval.
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Ankit Mehta@Secvyn
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Detections.ai Community
4 months ago
207
This rule detects the use of TLS protocol on port 443 with a specific content signature, indicating potential Command and Control (C2) activity. It triggers an alert if 20 such connections are observed from the same source within 60 seconds.
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Darshan Thummar@Mighty
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Detections.ai Community
4 months ago
002
This rule detects potential command and control (C2) beaconing activity associated with Mythic implants. It monitors for high-frequency outbound connections (20 or more) from a single device to the same external IP address within a 30-minute window across common C2 listener ports (80, 443, 8080, 8443, 7443).
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Ankit Mehta@Secvyn
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Detections.ai Community
4 months ago
002
This rule detects potential command and control (C2) beaconing activity by identifying non-browser processes that initiate regular, sustained outbound network connections over port 443. It aggregates connection data by hour and calculates metrics such as average frequency and standard deviation to identify consistent, periodic communication patterns characteristic of C2 agents while excluding common legitimate web browsers.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
101
This rule detects potential command and control (C2) beaconing activity by identifying non-browser processes that initiate regular, sustained outbound network connections over port 443. It aggregates connection data by hour and calculates metrics such as average frequency and standard deviation to identify consistent, periodic communication patterns characteristic of C2 agents while excluding common legitimate web browsers.
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Ankit Mehta@Secvyn
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Detections.ai Community
4 months ago
101
Detects high-cardinality, multi-protocol network scanning behavior characteristic of the JDY botnet. The rule identifies internal hosts attempting to connect to a high volume of unique external destinations across multiple protocols with low average bytes per connection, indicative of automated discovery or probing activity.
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Ibrahim Saud@tektrix
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Detections.ai Community
4 months ago
001
This rule detects outbound network traffic from internal IP addresses to known Tor network entry or exit relay ports (9001, 9030, 9050, 9051). It specifically prioritizes alerts where the source host is identified as network infrastructure (routers, gateways, firewalls) or IoT devices, flagging potential unauthorized use of Tor for obfuscated communication or data exfiltration from within the network perimeter.
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Ibrahim Saud@tektrix
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Detections.ai Community
4 months ago
001
Detects the transmission of plaintext 'OfflineFrame' protocol messages (such as CONNECTIONRESPONSE, BANDWIDTHUPGRADE, or KEEPALIVE) within the 'Nearby Connections' protocol that lack required encryption ('SecureMessage') after the UKEY2 key exchange phase. This behavior indicates a potential misconfiguration or an attempt to intercept/manipulate Nearby Connections traffic.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
001
Detects the transmission of plaintext 'OfflineFrame' protocol messages (such as CONNECTIONRESPONSE, BANDWIDTHUPGRADE, or KEEPALIVE) within the 'Nearby Connections' protocol that lack required encryption ('SecureMessage') after the UKEY2 key exchange phase. This behavior indicates a potential misconfiguration or an attempt to intercept/manipulate Nearby Connections traffic.
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Ankit Mehta@Secvyn
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Detections.ai Community
4 months ago
001
Detects anomalous SMB traffic indicating potential ransomware activity. The rule monitors for file operations associated with known ransomware naming conventions (e.g., README.txt, DECRYPT_INSTRUCTIONS) or common ransomware-related extensions. It uses a threshold to identify high-frequency occurrences within a short timeframe, suggesting bulk file renaming or ransom note creation typical of encryption phases.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
001
This rule detects potential command and control (C2) beaconing activity using DNS tunneling. It monitors for a high frequency of DNS TXT record queries to long subdomains (exceeding 50 characters), which is a common characteristic of tools like DNScat and iodine that encode data within DNS requests.
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Ankit Mehta@Secvyn
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Detections.ai Community
4 months ago
001
Detects anomalous SMB traffic indicating potential ransomware activity. The rule monitors for file operations associated with known ransomware naming conventions (e.g., README.txt, DECRYPT_INSTRUCTIONS) or common ransomware-related extensions. It uses a threshold to identify high-frequency occurrences within a short timeframe, suggesting bulk file renaming or ransom note creation typical of encryption phases.
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Ankit Mehta@Secvyn
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Detections.ai Community
4 months ago
001
This rule detects potential command and control (C2) beaconing activity by identifying devices communicating with known suspicious remote IP addresses at regular, repeating intervals. It calculates the time difference between consecutive connections to specific suspicious IPs and identifies devices that establish at least three connections within one-hour bins, adhering to a 1 to 15-minute heartbeat interval.
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
105
Detects network traffic associated with DcRAT malware, specifically monitoring outbound connections on port 2671 to external non-private IP addresses, or directly to known malicious infrastructure (223.26.63.40). The rule also identifies potential beaconing behavior by analyzing connection intervals and standard deviation, and flags activity originating from specific autonomous system ranges (AS152194) linked to the threat actor's infrastructure.
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Ibrahim Saud@tektrix
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Detections.ai Community
4 months ago
003
This rule detects potential command and control (C2) beaconing activity by identifying devices communicating with known suspicious remote IP addresses at regular, repeating intervals. It calculates the time difference between consecutive connections to specific suspicious IPs and identifies devices that establish at least three connections within one-hour bins, adhering to a 1 to 15-minute heartbeat interval.
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Ankit Mehta@Secvyn
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Detections.ai Community
4 months ago
001
This rule detects potential command and control (C2) beaconing activity associated with Mythic implants. It monitors for high-frequency outbound connections (20 or more) from a single device to the same external IP address within a 30-minute window across common C2 listener ports (80, 443, 8080, 8443, 7443).
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Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
101
Detects HTTP response bodies containing specific strings associated with the 'Montana Empire' phishing kit. This rule monitors for indicators that a web server is serving a phishing credential harvesting page.
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Duo Tech@duotech
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Detections.ai Community
4 months ago
000
Detects network flows to RustDesk relay server ports (21115, 21116, 21117) characterized by anomalous connection patterns. The rule identifies hosts exhibiting rapid, repeated connection attempts or connections to multiple distinct relay IP addresses within a short timeframe. This behavior is consistent with the 'rustdesk-session-permission-pocs' technique, which may indicate an attacker attempting to establish a remote session while bypassing the standard permission handshake exchange required by the application.
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Ethan Andrews@eandrews
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Federal Signal Detections
4 months ago
001
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