Detections

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

74 detections

Detects a root SSH sign-in from a public IP address or known attacker IP, followed within 30 minutes by a write or modification to the root authorized_keys file on the same device.
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ills3c Intel&Coffee@Ills3C
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Detections.ai Community
5 days ago
207
Detects modification of a monitored file on a Centrify-managed Linux host. File
integrity events on Unix servers catch tampering with configuration, authorised keys
and service definitions — the common Linux persistence routes, which leave no
registry trace and no Windows-style artefact.

Onboarding: CENTRIFY-AUDITTRAIL-LINUX is ingested via Syslog (KV) (Bloo extractor 822).
Integration guide: https://bloo.io/docs/hypercloud/syslog-connector

BQL (Bloo Query Language):

stream=iam where sourcename='CENTRIFY-AUDITTRAIL-LINUX' and action='FILE_MODIFIED'
| groupby user, targetuser, domain
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Siddhant Mishra@Siddhant
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Bloo SpecterForce
7 days ago
000
The following analytic detects the modification of SSH Authorized Keys on Linux systems. It leverages process execution data from Endpoint Detection and Response (EDR) agents, specifically monitoring commands like "bash" and "cat" interacting with "authorized_keys" files. This activity is significant as adversaries often modify SSH Authorized Keys to establish persistent access to compromised endpoints. If confirmed malicious, this behavior could allow attackers to maintain unauthorized access, bypassing traditional authentication mechanisms and potentially leading to further exploitation or data exfiltration.
Splunk Security@SplunkSecurity
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Splunk Security Content
16 days ago
504
Detects evidence of exploitation and post-exploitation activity related to CVE-2026-59310, an unauthenticated RCE vulnerability in the VMware vCenter Syslog Server. The rule monitors for suspicious child processes spawned by vmsyslogcollector, directory traversal patterns in command lines, and persistence mechanisms involving SSH authorized_keys modification, cron job creation, or systemd unit deployment on the VCSA shell.
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Ankit Mehta@Secvyn
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Detections.ai Community
27 days ago
608
Detects potential misuse of SSH credentials by identifying successful SSH logins from source IP addresses that have not been observed in the previous 14 days, or successful SSH logins occurring within one hour of an authorized_keys file modification on the same host. This combination of behaviors is indicative of an adversary establishing or using persistence via SSH key manipulation.
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Ankit Mehta@Secvyn
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SlimKQL
27 days ago
1006
Detects the creation or modification of SSH authorized_keys or authorized_keys2 files. This is a common persistence technique used to maintain remote access by adding an adversary-controlled public key to a user's configuration, often performed after initial access through exploitation of public-facing services.
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Ibrahim Saud@tektrix
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Detections.ai Community
30 days ago
207
This rule identifies suspicious post-exploitation activity where an anomalous or unauthenticated NetScaler VPN session (potentially exploiting CVE-2026-88771 or CVE-2026-88772) is followed by the creation or modification of SSH authorized_keys files or related credential manipulation commands on internal hosts, suggesting an attacker establishing persistence.
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Ibrahim Saud@tektrix
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Detections.ai Community
30 days ago
006
Detects potential misuse of SSH credentials by identifying successful SSH logins from source IP addresses that have not been observed in the previous 14 days, or successful SSH logins occurring within one hour of an authorized_keys file modification on the same host. This combination of behaviors is indicative of an adversary establishing or using persistence via SSH key manipulation.
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Ankit Mehta@Secvyn
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Detections.ai Community
27 days ago
002
Detects unauthorized modifications to the .ssh/authorized_keys file. Such changes are often performed by adversaries to establish persistence by ensuring their own public keys allow them remote access to the host. The rule filters out known configuration management and system tools to reduce noise.
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Ibrahim Saud@tektrix
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Detections.ai Community
27 days ago
002
Detects potential abuse of Cloud Shell to persist access in cloud environments. For GCP, it monitors the injection of SSH keys into instance or project metadata from a Cloud Shell session. For Azure, it detects a pattern involving Cloud Shell storage provisioning followed by a subsequent VM run-command or SSH public key update, indicating potential unauthorized management of virtual machines.
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Ibrahim Saud@tektrix
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Detections.ai Community
27 days ago
201
Detects instances where the Redis server process or the Redis AOF check utility writes directly to common SSH authorized_keys file paths. This behavior is indicative of an attacker exploiting a Redis misconfiguration or vulnerability (e.g., Redis RCE) to establish persistence by injecting an unauthorized SSH key.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
005
Detects potential abuse of Cloud Shell to persist access in cloud environments. For GCP, it monitors the injection of SSH keys into instance or project metadata from a Cloud Shell session. For Azure, it detects a pattern involving Cloud Shell storage provisioning followed by a subsequent VM run-command or SSH public key update, indicating potential unauthorized management of virtual machines.
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Ibrahim Saud@tektrix
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Detections.ai Community
27 days ago
000
This rule detects suspicious activity associated with Redis server processes attempting to write to SSH 'authorized_keys' files or executing commands (such as BGREWRITEAOF or directory reconfiguration) commonly used by attackers to inject malicious SSH public keys into a Redis installation for persistent remote access.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
004
Detects unauthorized modifications to SSH authorized_keys files. Attackers often modify these files to inject their own public keys, ensuring persistent access to a compromised Linux host. This rule excludes known configuration management and provisioning tools to reduce noise.
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Ibrahim Saud@tektrix
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Detections.ai Community
1 month ago
002
Detects SSH persistence planted during the Red Heron campaign: authorized_keys file writes under a .ssh folder, correlated with process command lines referencing authorized_keys and the operator's observed key comment naming pattern (backdoor / root-shell).
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Arnold Chan@slaz
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Detection & Hunting Community
1 month ago
003
Detects SSH persistence planted during the Red Heron campaign: authorized_keys file writes under a .ssh folder, correlated with process command lines referencing authorized_keys and the operator's observed key comment naming pattern (backdoor / root-shell).
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Arnold Chan@slaz
Defender - KQL
1 month ago
002
Detects SSH persistence planted during the Red Heron campaign: authorized_keys file writes under a .ssh folder, correlated with process command lines referencing authorized_keys and the operator's observed key comment naming pattern (backdoor / root-shell).
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Arnold Chan@slaz
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Hunters
1 month ago
002
This rule detects modifications or creation of the SSH 'authorized_keys' file, often used to establish unauthorized persistent access via SSH key-based authentication. It monitors both file system changes and command-line execution patterns involving SSH key injection commands (e.g., echo, cat, redirection) while filtering out known management agent activity.
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Arnold Chan@slaz
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Detection & Hunting Community
1 month ago
001
This rule detects modifications or creation of the SSH 'authorized_keys' file, often used to establish unauthorized persistent access via SSH key-based authentication. It monitors both file system changes and command-line execution patterns involving SSH key injection commands (e.g., echo, cat, redirection) while filtering out known management agent activity.
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Arnold Chan@slaz
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Midnight Slayer
1 month ago
001
This rule detects modifications or creation of the SSH 'authorized_keys' file, often used to establish unauthorized persistent access via SSH key-based authentication. It monitors both file system changes and command-line execution patterns involving SSH key injection commands (e.g., echo, cat, redirection) while filtering out known management agent activity.
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Arnold Chan@slaz
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Hunters
1 month ago
001
This rule detects modifications or creation of the SSH 'authorized_keys' file, often used to establish unauthorized persistent access via SSH key-based authentication. It monitors both file system changes and command-line execution patterns involving SSH key injection commands (e.g., echo, cat, redirection) while filtering out known management agent activity.
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Arnold Chan@slaz
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Detections.ai Community
1 month ago
001
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