EXPLORE DETECTIONS
Detect Regsvcs with Network Connection
The following analytic identifies instances of Regsvcs.exe establishing a network connection to a public IP address, excluding private IP ranges. This detection leverages Sysmon EventID 3 logs to monitor network connections initiated by Regsvcs.exe. This activity is significant as Regsvcs.exe, a legitimate Microsoft-signed binary, can be exploited to bypass application control mechanisms and establish remote Command and Control (C2) channels. If confirmed malicious, this behavior could allow an attacker to escalate privileges, persist in the environment, and exfiltrate sensitive data. Immediate investigation and remediation are recommended.
Detect Regsvcs with No Command Line Arguments
The following analytic detects instances of regsvcs.exe running without command line arguments. This behavior typically indicates process injection, where another process manipulates regsvcs.exe. The detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, IDs, and command-line executions. This activity is significant as it may signal an attempt to evade detection and execute malicious code. If confirmed malicious, the attacker could achieve code execution, potentially leading to privilege escalation, persistence, or access to sensitive information.
Detect Regsvr32 Application Control Bypass
The following analytic identifies the abuse of Regsvr32.exe to proxy execution of malicious code, specifically detecting the loading of "scrobj.dll" by Regsvr32.exe. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events and command-line executions. This activity is significant because Regsvr32.exe is a trusted, signed Microsoft binary, often used in "Squiblydoo" attacks to bypass application control mechanisms. If confirmed malicious, this technique could allow an attacker to execute arbitrary code, potentially leading to system compromise and persistent access.
Detect Remote Access Software Usage DNS
The following analytic detects DNS queries to domains associated with known remote access software such as AnyDesk, GoToMyPC, LogMeIn, and TeamViewer. This detection is crucial as adversaries often use these tools to maintain access and control over compromised environments. Identifying such behavior is vital for a Security Operations Center (SOC) because unauthorized remote access can lead to data breaches, ransomware attacks, and other severe impacts if these threats are not mitigated promptly.
Detect Remote Access Software Usage File
The following analytic detects the writing of files from known remote access software to disk within the environment. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on file path, file name, and user information. This activity is significant as adversaries often use remote access tools like AnyDesk, GoToMyPC, LogMeIn, and TeamViewer to maintain unauthorized access. If confirmed malicious, this could allow attackers to persist in the environment, potentially leading to data exfiltration, further compromise, or complete control over affected systems. It is best to update both the remote_access_software_usage_exception.csv lookup and the remote_access_software lookup with any known or approved remote access software to reduce false positives and increase coverage. In order to enhance performance, the detection filters for specific file names extensions / names that are used in the remote_access_software lookup. If add additional entries, consider updating the search filters to include those file names / extensions as well, if not alread covered.
Detect Remote Access Software Usage FileInfo
The following analytic detects the execution of processes with file or code signing attributes from known remote access software within the environment. It leverages Sysmon EventCode 1 data and cross-references a lookup table of remote access utilities such as AnyDesk, GoToMyPC, LogMeIn, and TeamViewer. This activity is significant as adversaries often use these tools to maintain unauthorized remote access. If confirmed malicious, this could allow attackers to persist in the environment, potentially leading to data exfiltration or further compromise of the network.
Detect Remote Access Software Usage Process
The following analytic detects the execution of known remote access software within the environment. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and parent processes mapped to the Endpoint data model. We then compare with with a list of known remote access software shipped as a lookup file - remote_access_software. This activity is significant as adversaries often use remote access tools like AnyDesk, GoToMyPC, LogMeIn, and TeamViewer to maintain unauthorized access. If confirmed malicious, this could allow attackers to control systems remotely, exfiltrate data, or deploy additional malware, posing a severe threat to the organization's security.
Detect Remote Access Software Usage Registry
The following analytic detects when a known remote access software is added to common persistence locations on a device within the environment. Adversaries use these utilities to retain remote access capabilities to the environment. Utilities in the lookup include AnyDesk, GoToMyPC, LogMeIn, TeamViewer and much more. Review the lookup for the entire list and add any others.
Detect Remote Access Software Usage Traffic
The following analytic detects network traffic associated with known remote access software applications, such as AnyDesk, GoToMyPC, LogMeIn, and TeamViewer. It leverages Palo Alto traffic logs mapped to the Network_Traffic data model in Splunk. This activity is significant because adversaries often use remote access tools to maintain unauthorized access to compromised environments. If confirmed malicious, this activity could allow attackers to control systems remotely, exfiltrate data, or deploy additional malware, posing a severe threat to the organization's security.
Detect Remote Access Software Usage URL
The following analytic detects the execution of known remote access software within the environment. It leverages network logs mapped to the Web data model, identifying specific URLs and user agents associated with remote access tools like AnyDesk, GoToMyPC, LogMeIn, and TeamViewer. This activity is significant as adversaries often use these utilities to maintain unauthorized remote access. If confirmed malicious, this could allow attackers to control systems remotely, exfiltrate data, or further compromise the network, posing a severe security risk.
Detect Renamed 7-Zip
The following analytic detects the usage of a renamed 7-Zip executable using Sysmon data. It leverages the OriginalFileName field to identify instances where the 7-Zip process has been renamed. This activity is significant as attackers often rename legitimate tools to evade detection while staging or exfiltrating data. If confirmed malicious, this behavior could indicate data exfiltration attempts or other unauthorized data manipulation, potentially leading to significant data breaches or loss of sensitive information. Analysts should validate the legitimacy of the 7-Zip executable and investigate parallel processes for further suspicious activities.
Detect Renamed PSExec
The following analytic identifies instances where `PsExec.exe` has been renamed and executed on an endpoint. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and original file names. This activity is significant because renaming `PsExec.exe` is a common tactic to evade detection. If confirmed malicious, this could allow an attacker to execute commands remotely, potentially leading to unauthorized access, lateral movement, or further compromise of the network.
Detect Renamed RClone
The following analytic detects the execution of a renamed `rclone.exe` process, which is commonly used for data exfiltration to remote destinations. This detection leverages Endpoint Detection and Response (EDR) telemetry, focusing on process names and original file names that do not match. This activity is significant because ransomware groups often use RClone to exfiltrate sensitive data. If confirmed malicious, this behavior could indicate an ongoing data exfiltration attempt, potentially leading to significant data loss and further compromise of the affected systems.
Detect Renamed WinRAR
The following analytic identifies instances where `WinRAR.exe` has been renamed and executed. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and original file names within the Endpoint data model. This activity is significant because renaming executables is a common tactic used by attackers to evade detection. If confirmed malicious, this could indicate an attempt to bypass security controls, potentially leading to unauthorized data extraction or further system compromise.
Detect Rogue DHCP Server
The following analytic identifies the presence of unauthorized DHCP servers on the network. It leverages logs from Cisco network devices with DHCP Snooping enabled, specifically looking for events where DHCP leases are issued from untrusted ports. This activity is significant because rogue DHCP servers can facilitate Man-in-the-Middle attacks, leading to potential data interception and network disruption. If confirmed malicious, this could allow attackers to redirect network traffic, capture sensitive information, and compromise the integrity of the network.
Detect RTLO In File Name
The following analytic identifies the use of the right-to-left override (RTLO) character in file names. It leverages data from the Endpoint.Filesystem datamodel, specifically focusing on file creation events and file names containing the RTLO character (U+202E). This activity is significant because adversaries use RTLO to disguise malicious files as benign by reversing the text that follows the character. If confirmed malicious, this technique can deceive users and security tools, leading to the execution of harmful files and potential system compromise.
Detect RTLO In Process
The following analytic identifies the abuse of the right-to-left override (RTLO) character (U+202E) in process names. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs and command-line data. This activity is significant because adversaries use the RTLO character to disguise malicious files or commands, making them appear benign. If confirmed malicious, this technique can allow attackers to execute harmful code undetected, potentially leading to unauthorized access, data exfiltration, or further system compromise.
Detect Rundll32 Inline HTA Execution
The following analytic detects the execution of "rundll32.exe" with inline protocol handlers such as "JavaScript", "VBScript", and "About". This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on command-line arguments. This activity is significant as it is often associated with fileless malware or application whitelisting bypass techniques. If confirmed malicious, this could allow an attacker to execute arbitrary code, bypass security controls, and maintain persistence within the environment.
Detect S3 access from a new IP
The following analytic identifies access to an S3 bucket from a new or previously unseen remote IP address. It leverages S3 bucket-access logs, specifically focusing on successful access events (http_status=200). This activity is significant because access from unfamiliar IP addresses could indicate unauthorized access or potential data exfiltration attempts. If confirmed malicious, this activity could lead to unauthorized data access, data theft, or further exploitation of the compromised S3 bucket, posing a significant risk to sensitive information stored within the bucket.
Detect SharpHound Command-Line Arguments
The following analytic detects the execution of SharpHound command-line arguments, specifically `-collectionMethod` and `invoke-bloodhound`. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as SharpHound is commonly used for Active Directory enumeration, which can be a precursor to lateral movement or privilege escalation. If confirmed malicious, this activity could allow an attacker to map out the network, identify high-value targets, and plan further attacks, potentially compromising sensitive information and critical systems.
Detect SharpHound File Modifications
The following analytic detects the creation of files typically associated with SharpHound, a reconnaissance tool used for gathering domain and trust data. It leverages file modification events from the Endpoint.Filesystem data model, focusing on default file naming patterns like `*_BloodHound.zip` and various JSON files. This activity is significant as it indicates potential domain enumeration, which is a precursor to more targeted attacks. If confirmed malicious, an attacker could gain detailed insights into the domain structure, facilitating lateral movement and privilege escalation.
Detect SharpHound Usage
The following analytic detects the usage of the SharpHound binary by identifying its original filename, `SharpHound.exe`, and the process name. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process metadata and command-line executions. SharpHound is a tool used for Active Directory enumeration, often by attackers during the reconnaissance phase. If confirmed malicious, this activity could allow an attacker to map out the network, identify high-value targets, and plan further attacks, potentially leading to privilege escalation and lateral movement within the environment.
Detect SNICat SNI Exfiltration
The following analytic identifies the use of SNICat tool commands within the TLS SNI field, indicating potential data exfiltration attempts. It leverages Zeek SSL data to detect specific SNICat commands such as LIST, LS, SIZE, LD, CB, EX, ALIVE, EXIT, WHERE, and finito in the server_name field. This activity is significant as SNICat is a known tool for covert data exfiltration using TLS. If confirmed malicious, this could allow attackers to exfiltrate sensitive data undetected, posing a severe threat to data confidentiality and integrity.
Detect Software Download To Network Device
The following analytic identifies unauthorized software downloads to network devices via TFTP, FTP, or SSH/SCP. It detects this activity by analyzing network traffic events on specific ports (69, 21, 22) from devices categorized as network, router, or switch. This activity is significant because adversaries may exploit netbooting to load unauthorized operating systems, potentially compromising network integrity. If confirmed malicious, this could lead to unauthorized control over network devices, enabling further attacks, data exfiltration, or persistent access within the network.