Windows High File Deletion Frequency: endpointEndpointNoneversion:15
The following analytic identifies a high frequency of file deletions by monitoring Sysmon EventCodes 23 and 26 for specific file extensions. This detection leverages Sysmon logs to track deleted target filenames, process names, and process IDs. Such activity is significant as it often indicates ransomware behavior, where files are encrypted and the originals are deleted. If confirmed malicious, this activity could lead to extensive data loss and operational disruption, as ransomware can render critical files inaccessible, demanding a ransom for their recovery.
Windows System Shutdown CommandLine: endpointEndpointNoneversion:14
The following analytic identifies the execution of the Windows shutdown command via the command line interface. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments. This activity is significant because attackers may use the shutdown command to erase tracks, cause disruption, or ensure changes take effect after installing backdoors. If confirmed malicious, this activity could lead to system downtime, denial of service, or evasion of security tools, impacting the overall security posture of the network.
Rubeus Kerberos Ticket Exports Through Winlogon Access: endpointEndpointNoneversion:15
The following analytic detects an uncommon process requesting full access rights to winlogon.exe, which may indicate Rubeus exporting Kerberos tickets from memory.
It leverages Sysmon EventCode 10 and checks for full-access rights, specifically the value 0x1f3fff.
Modification Of Wallpaper: endpointEndpointNoneversion:11
The following analytic detects the modification of registry keys related to the desktop wallpaper settings. It leverages Sysmon EventCode 13 to identify changes to the "Control Panel\\Desktop\\Wallpaper" and "Control Panel\\Desktop\\WallpaperStyle" registry keys, especially when the modifying process is not explorer.exe or involves suspicious file paths like temp or public directories. This activity is significant as it can indicate ransomware behavior, such as the REVIL ransomware, which changes the wallpaper to display a ransom note. If confirmed malicious, this could signify a compromised machine and the presence of ransomware, leading to potential data encryption and extortion.
Windows Indicator Removal Via Rmdir: endpointEndpointNoneversion:13
The following analytic detects the execution of the 'rmdir' command with '/s' and '/q' options to delete files and directory trees. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process metadata. This activity is significant as it may indicate malware attempting to remove traces or components during cleanup operations. If confirmed malicious, this behavior could allow attackers to eliminate forensic evidence, hinder incident response efforts, and maintain persistence by removing indicators of compromise.
Rubeus Command Line Parameters: endpointEndpointNoneversion:13
The following analytic detects the use of Rubeus command line parameters, a toolset for Kerberos attacks within Active Directory environments. It leverages Endpoint Detection and Response (EDR) data to identify specific command-line arguments associated with actions like ticket manipulation, kerberoasting, and password spraying. This activity is significant as Rubeus is commonly used by adversaries to exploit Kerberos for privilege escalation and lateral movement. If confirmed malicious, this could lead to unauthorized access, persistence, and potential compromise of sensitive information within the network.
