Detections
Explore public detection logic contributed by the community across SIEM and rule languages.
219 detections
Filters
Last updated
All Time
Detection languages
109
46
38
12
5
Contributors
46
46
32
31
21
Categories
20,443
11,831
5,872
5,155
4,866
Platforms
158
61
34
25
4
Products / Services
115
75
58
19
18
MITRE Techniques
91
48
34
27
19
CVEs
4
2
1
1
1
IDS Classtypes
50
20
16
6
5
IDS Protocols
44
23
21
9
6
This rule detects the presence of a large Base64 encoded string (at least 100 characters) within the HTTP client body of network traffic. This pattern is often used by attackers to obfuscate malicious payloads, aligning with the MITRE ATT&CK technique T1027 for Defense Evasion.
This rule detects internal Server Message Block (SMB) lateral movement attempts. It triggers when there are 10 or more SMB connections (identified by the "|FF|SMB" content signature) from a single source IP address to any destination on port 445 within a 60-second window, within the home network. This behavior is indicative of an attacker attempting to move laterally within a network using SMB.
This rule identifies potential network scanning or high-volume communication by detecting a large number of connections (50 or more) between a single source IP and a single destination IP within a 5-minute time window. It aggregates connection details such as total connections, sent bytes, and received bytes from the CommonSecurityLog.
This rule detects a high number of distinct URLs and total network connections originating from a single remote IP address within a one-minute time window. This behavior can be indicative of various malicious activities such as data exfiltration, command and control (C2) communication, or network scanning. The threshold for distinct URLs is set to greater than 100 and total connections greater than 500.
This rule detects devices making a high volume of outbound network connections (more than 1000 connections within a one-minute window) to a single remote IP address. This behavior could indicate a network denial-of-service (DoS) attack originating from the device, or potentially other forms of high-volume network activity such as data exfiltration or scanning.
This rule detects instances where a single remote IP address exhibits a high number of idle network events (more than 200 idle events) and a high total number of network events (more than 500 total events) within a one-minute interval. This pattern can be indicative of Command and Control (C2) communication, where an adversary establishes a connection and then waits for commands, or data exfiltration, where data is sent in bursts with idle periods in between. It highlights unusual network communication patterns that might suggest malicious activity.
This rule identifies potential network scanning or high-volume communication by detecting a large number of connections (50 or more) between a single source IP and a single destination IP within a 5-minute time window. It aggregates connection details such as total connections, sent bytes, and received bytes from the CommonSecurityLog.
This rule detects suspicious network communication patterns indicative of command and control (C2) activity by analyzing the jitter (variability) in connection gaps and byte transfer sizes. It identifies connections with a high number of events, a consistent average gap between connections, and low jitter in both connection timing and data transfer sizes (bytes out and bytes in). This pattern can suggest automated, scheduled communication often associated with C2 channels.
The query, as constructed, is primarily focused on detecting large outbound traffic volumes to external destinations on a per source-destination pair basis within daily aggregations. Adjust the threshold and aggregation criteria based on your specific security requirements and typical network behavior patterns.
Detects ICMP Echo Request packets where the Identification field is set to the specific magic value 0xC0DE (49374). This value is used by the VoidLink rootkit as a trigger for its covert, out-of-band C2 channel, which can bypass standard firewall rules.
This rule detects Command and Control (C2) communication associated with the Mythic C2 framework utilizing Server Message Block (SMB) for peer-to-peer (P2P) beaconing. It specifically looks for SMB_COM_WRITE_ANDX commands with a data size greater than 360 bytes, containing a specific null byte pattern at offset 86, and a PCRE match for a GUID-like string, which are indicators of Mythic C2 SMB P2P beacon traffic.
ET INFO Observed VNT VPN Domain (vnt .wherewego .top in TLS SNI)
ET INFO Observed VNT VPN Domain (vnt .8443 .eu .org in TLS SNI)
This rule detects the usage of cleartext protocols for transmitting sensitive information, such as account usernames and authentication credentials, across networks. It specifically monitors Netflow data for connections to common ports associated with unencrypted services like HTTP, FTP, Telnet, and various database/application ports. The goal is to ensure that all sensitive data and administrative access utilize encrypted channels to prevent credential access and data interception.
Adversaries may intentionally suppress or reduce the volume of core Cisco ASA syslog messages to evade detection or cover their tracks. This hunting search is recommended to proactively identify suspicious downward shifts or absences in key syslog message IDs, which may indicate tampering or malicious activity. Visualizing this data in Splunk dashboards enables security teams to quickly spot anomalies and investigate potential compromise. The rule specifically looks for drops in message IDs 302013 (Built inbound TCP connection), 302014 (Teardown TCP connection), 609002 (Teardown local-host management), and 710005 (TCP request discarded).
This detection identifies execution of the file synchronization utility "rclone" with network activity, as captured by Cisco Network Visibility Module flow data. It specifically looks for `rclone.exe` or `rclone` commands with arguments indicative of data transfer to cloud storage providers (e.g., `copy`, `remote:`, `mega:`, `ftp:`) and suspicious flags (`--transfers`, `--ignore-existing`, `--auto-confirm`). Rclone is a legitimate tool but is frequently abused by threat actors for data exfiltration or cloud abuse.
This rule identifies network traffic to known Command and Control (C2) infrastructure associated with the Katz Stealer malware family. It uses a list of hardcoded IP addresses and domains from threat intelligence to detect suspicious outbound connections.
This rule detects potential proxy bypass attempts by identifying network connections on common web ports (80, 443) that are allowed by the network firewall but do not appear in the proxy logs. It correlates network traffic from the Network_Traffic data model with proxy traffic from the Web data model. The rule specifically filters for external-bound traffic by excluding private and multicast IP addresses.
KQL Query
The following analytic identifies anomalous network traffic volumes between Kubernetes workloads or between a workload and external sources. It leverages Network Performance Monitoring metrics collected via an OTEL collector and pulled from Splunk Observability Cloud. The detection compares recent network metrics (tcp.bytes, tcp.new_sockets, tcp.packets, udp.bytes, udp.packets) over the last hour with the average over the past 30 days to identify significant deviations. This activity is significant as unexpected spikes may indicate unauthorized data transfers or lateral movement. If confirmed malicious, it could lead to data exfiltration or compromise of additional services, potentially resulting in data breaches.
This analytic detects new UDP communication between a source and destination workload pair within a Kubernetes cluster. It uses Network Performance Monitoring (NPM) metrics from an OTEL collector via Splunk Observability Cloud. The detection compares network activity over the last hour with the past 30 days to identify new inter-workload communication. Such changes in network behavior can indicate potential security threats or anomalies, including unauthorized connections that may lead to data breaches, privilege escalation, lateral movement, or disruption of critical services.
Page 10 of 11