Samirbous
b15f0de9a4
* [Rules Tuning] 7 diverse Windows rules Excluding FP patterns while avoiding breaking compat with winlogbeat and 4688 events lack of codesign metadata. * Update initial_access_suspicious_ms_exchange_process.toml * Update privilege_escalation_persistence_phantom_dll.toml * Update execution_psexec_lateral_movement_command.toml * Update persistence_remote_password_reset.toml * Update non-ecs-schema.json * Update persistence_remote_password_reset.toml * Update non-ecs-schema.json * Update discovery_privileged_localgroup_membership.toml
114 lines
4.8 KiB
TOML
114 lines
4.8 KiB
TOML
[metadata]
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creation_date = "2020/02/18"
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maturity = "production"
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updated_date = "2022/08/02"
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[rule]
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author = ["Elastic"]
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description = """
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Identifies use of the SysInternals tool PsExec.exe making a network connection. This could be an indication of lateral
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movement.
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"""
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false_positives = [
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"""
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PsExec is a dual-use tool that can be used for benign or malicious activity. It's important to baseline your
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environment to determine the amount of noise to expect from this tool.
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""",
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]
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from = "now-9m"
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index = ["winlogbeat-*", "logs-endpoint.events.*", "logs-windows.*"]
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language = "eql"
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license = "Elastic License v2"
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name = "PsExec Network Connection"
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note = """## Triage and analysis
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### Investigating PsExec Network Connection
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PsExec is a remote administration tool that enables the execution of commands with both regular and SYSTEM privileges
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on Windows systems. Microsoft develops it as part of the Sysinternals Suite. Although commonly used by administrators,
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PsExec is frequently used by attackers to enable lateral movement and execute commands as SYSTEM to disable defenses and
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bypass security protections.
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This rule identifies PsExec execution by looking for the creation of `PsExec.exe`, the default name for the
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utility, followed by a network connection done by the process.
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#### Possible investigation steps
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- Check if the usage of this tool complies with the organization's administration policy.
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- Investigate the process execution chain (parent process tree) for unknown processes. Examine their executable files
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for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.
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- Investigate other alerts associated with the user/host during the past 48 hours.
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- Identify the user account that performed the action and whether it should perform this kind of action.
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- Identify the target computer and its role in the IT environment.
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- Investigate what commands were run, and assess whether this behavior is prevalent in the environment by looking for
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similar occurrences across hosts.
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### False positive analysis
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- This mechanism can be used legitimately. As long as the analyst did not identify suspicious activity related to the
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user or involved hosts, and the tool is allowed by the organization's policy, such alerts can be dismissed.
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### Response and remediation
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- Initiate the incident response process based on the outcome of the triage.
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- Prioritize accordingly with the role of the servers and users involved.
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- Isolate the involved hosts to prevent further post-compromise behavior.
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- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are
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identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business
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systems, and web services.
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- Run a full scan using the antimalware tool in place. This scan can reveal additional artifacts left in the system,
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persistence mechanisms, and malware components.
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- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.
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- Review the privileges assigned to the user to ensure that the least privilege principle is being followed.
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- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the
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mean time to respond (MTTR).
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"""
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risk_score = 21
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rule_id = "55d551c6-333b-4665-ab7e-5d14a59715ce"
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severity = "low"
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tags = ["Elastic", "Host", "Windows", "Threat Detection", "Execution"]
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type = "eql"
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query = '''
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sequence by process.entity_id
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[process where process.name : "PsExec.exe" and event.type == "start" and
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/* This flag suppresses the display of the license dialog and may
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indicate that psexec executed for the first time in the machine */
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process.args : "-accepteula" and
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not process.executable : ("?:\\ProgramData\\Docusnap\\Discovery\\discovery\\plugins\\17\\Bin\\psexec.exe",
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"?:\\Docusnap 11\\Bin\\psexec.exe",
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"?:\\Program Files\\Docusnap X\\Bin\\psexec.exe",
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"?:\\Program Files\\Docusnap X\\Tools\\dsDNS.exe") and
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not process.parent.executable : "?:\\Program Files (x86)\\Cynet\\Cynet Scanner\\CynetScanner.exe"]
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[network where process.name : "PsExec.exe"]
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'''
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[[rule.threat]]
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framework = "MITRE ATT&CK"
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[[rule.threat.technique]]
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id = "T1569"
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name = "System Services"
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reference = "https://attack.mitre.org/techniques/T1569/"
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[[rule.threat.technique.subtechnique]]
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id = "T1569.002"
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name = "Service Execution"
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reference = "https://attack.mitre.org/techniques/T1569/002/"
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[rule.threat.tactic]
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id = "TA0002"
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name = "Execution"
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reference = "https://attack.mitre.org/tactics/TA0002/"
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[[rule.threat]]
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framework = "MITRE ATT&CK"
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[rule.threat.tactic]
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id = "TA0008"
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name = "Lateral Movement"
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reference = "https://attack.mitre.org/tactics/TA0008/"
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