Detections

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

77 detections

Detects anomalous network communication patterns and file system changes indicative of SoftEther VPN usage, particularly when linked to processes masquerading as VMware or communicating with known malicious C2 infrastructure. The rule monitors for network connections on common SoftEther ports, connections to specific command-and-control IP addresses, and the creation of SoftEther configuration files like 'hamcore.se2' or 'vpn_bridge.config'.
avatar
Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
000
This rule detects potential command and control (C2) communication over TCP that uses AES encryption with a hardcoded key pattern. It specifically looks for the byte sequence "41 45 53" (which corresponds to the ASCII string "AES") within the payload of a TCP flow from the internal network to any external destination. The rule further refines detection by checking for a payload size between 100 and 500 bytes and applies a threshold of 20 occurrences within 60 seconds from the same source IP to reduce false positives. This pattern is indicative of certain malware families that use predictable AES keying for their C2 channels.
avatar
Darshan Thummar@Mighty
avatar
Detections.ai Community
5 months ago
006
This rule detects HTTP POST requests with a client body that appears to be RC4 symmetric encrypted C2 beacon traffic. It specifically looks for HTTP traffic flowing to the server, with a client body between 100 and 500 bytes in size, and whose content matches a PCRE regex for base64 encoded strings. The rule is thresholded to trigger if 20 such events occur from the same source IP within 60 seconds, indicating potential beaconing activity.
avatar
Darshan Thummar@Mighty
avatar
Detections.ai Community
5 months ago
004
Detects instances of the openssl command-line tool being used to encrypt data with AES-256-CBC and RSA OAEP padding. This specific sequence matches the credential encryption pattern observed in the Linux/macOS payload of the malicious telnyx PyPI package attributed to TeamPCP.
avatar
Ethan Andrews@eandrews
avatar
Federal Signal Detections
7 months ago
110129
Detects the specific OpenSSL command line arguments used by TeamPCP (Trivy compromise) to encrypt stolen credentials before exfiltration using a hybrid AES-256-CBC scheme. This rule looks for the 'openssl' executable being run with 'enc -aes-256-cbc' or 'enc -aes-256' and a passphrase specified via a file using '-pass file:'.
avatar
Tim Peck@timpeck
avatar
Detections.ai Community
7 months ago
100160
Detects Sinobi Ransomware (suspected Lynx rebrand) payloads based on specific command-line arguments, help menu strings, ransom note URLs, and references to Curve-25519 and AES-128-CTR encryption routines.
avatar
Prakas Thevendaran@prakastheven
avatar
Detections.ai Community
7 months ago
0049
This rule detects attempts to use outdated or weak cryptographic algorithms and protocols by monitoring command-line arguments of common network and cryptographic utilities. Specifically, it looks for the use of RC4, DES, 3DES, RSA1024, MD5 ciphers, or TLS 1.0, TLS 1.1, and SSL 3.0 protocols, as well as the '--insecure' flag, when executed by applications like openssl, gpg, ssh, or curl. This could indicate an adversary attempting to downgrade cryptographic protections to facilitate eavesdropping or other attacks.
avatar
Danny Y@zendannyy
avatar
Detections.ai Community
8 months ago
30112
Pulsar RAT is a derivative of Quasar RAT with extensive functionality including keylogging, cryptocurrency wallet clipping, credential theft, file management, remote shell execution, and data exfiltration capabilities. As a modular, open-source remote administration tool designed for Windows systems, Pulsar introduces significant enhancements over its predecessor.
avatar
Wambua Thyaka@thyaka
avatar
Detections.ai Community
9 months ago
360249
Detects the unique User-Agent string "A WinHTTP Example Program/1.0" used by the MuddyViper backdoor for C2 communications, as reported in the MuddyWater campaign.
avatar
Tim Peck@timpeck
avatar
Detections.ai Community
11 months ago
30132
SesameOP Uses OpenAI Assistants API as a mechanism for command-and-control (C2) communications. Instead of relying on more traditional methods, the threat actor behind this backdoor abuses OpenAI as a C2 channel as a way to stealthily communicate and orchestrate malicious activities within the compromised environment. To do this, a component of the backdoor uses the OpenAI Assistants API as a storage or relay mechanism to fetch commands, which the malware then runs.
avatar
Wambua Thyaka@thyaka
avatar
Detections.ai Community
1 year ago
390204
This rule detects the Cruloader malware based on specific strings found within its binaries. The first rule, 'Loader_Cruloader_Strings', identifies the malware by looking for an RC4 key, a ROT13 charset, and the string "cruloader" itself. The second rule, 'Loader_Cruloader_Crypto', identifies the malware by looking for specific byte patterns indicative of its cryptographic routines, likely related to its RC4 implementation.
100daysofyara 2025@100daysyara2025
avatar
100 Days of YARA 2025
1 year ago
0060
KQL Query from file: Check for Entra Legacy TLS Login
avatar
Steven Lim@KQLWizard
avatar
SlimKQL
1 year ago
6082
This query checks for network connection failures to Microsoft Defender for Endpoint URLs.
The output includes any device with 1+ connectivity failures, a list of the domains they
failed to connect to (including the number of failures), as well as the overall number of
failures in the time period. Results are sorted by the total number of connection failures
by the device.
Azure Sentinel@AzureSentinel
avatar
AzureSentinel
1 year ago
0038
This rule detects the Voldemort backdoor by identifying specific byte patterns related to its configuration decryption, general decryption algorithm, access token request mechanism, network communication routines, and data download functions from its command and control (C2) server. The rule looks for a combination of these distinct code segments within a Windows executable (MZ header).
ReversingLabs Yara@ReversingLabsYara
avatar
ReversingLabs Yara
2 years ago
0030
Page 4 of 4