Jonhnathan
7c90f1d4c4
* Initial commit
* Update Investigation guides - security-docs review
* Update command_and_control_dns_tunneling_nslookup.toml
* Update defense_evasion_amsienable_key_mod.toml
* Apply security-docs review
* Remove dot
* Update rules/windows/command_and_control_rdp_tunnel_plink.toml
Co-authored-by: nastasha-solomon <79124755+nastasha-solomon@users.noreply.github.com>
* Apply changes from review
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Co-authored-by: nastasha-solomon <79124755+nastasha-solomon@users.noreply.github.com>
(cherry picked from commit 817b97f428)
96 lines
4.2 KiB
TOML
96 lines
4.2 KiB
TOML
[metadata]
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creation_date = "2020/11/25"
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maturity = "production"
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updated_date = "2022/05/09"
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[rule]
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author = ["Elastic"]
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description = """
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Identifies registry write modifications to enable Remote Desktop Protocol (RDP) access. This could be indicative of
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adversary lateral movement preparation.
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"""
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from = "now-9m"
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index = ["logs-endpoint.events.*", "winlogbeat-*", "logs-windows.*"]
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language = "eql"
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license = "Elastic License v2"
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name = "RDP Enabled via Registry"
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note = """## Triage and analysis
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### Investigating RDP Enabled via Registry
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Microsoft Remote Desktop Protocol (RDP) is a proprietary Microsoft protocol that enables remote connections to other
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computers, typically over TCP port 3389.
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Attackers can use RDP to conduct their actions interactively. Ransomware operators frequently use RDP to access
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victim servers, often using privileged accounts.
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This rule detects modification of the fDenyTSConnections registry key to the value `0`, which specifies that remote
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desktop connections are enabled. Attackers can abuse remote registry, use psexec, etc., to enable RDP and move laterally.
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#### Possible investigation steps
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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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- Contact the user to check if they are aware of the operation.
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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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- Check whether it makes sense to enable RDP to this host, given its role in the environment.
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- Check if the host is directly exposed to the internet.
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- Check whether privileged accounts accessed the host shortly after the modification.
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- Review network events within a short timespan of this alert for incoming RDP connection attempts.
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### False positive analysis
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- This mechanism can be used legitimately. Check whether the user should be performing this kind of activity, whether
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they are aware of it, whether RDP should be open, and whether the action exposes the environment to unnecessary risks.
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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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- If RDP is needed, make sure to secure it using firewall rules:
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- Allowlist RDP traffic to specific trusted hosts.
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- Restrict RDP logins to authorized non-administrator accounts, where possible.
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- Isolate the involved hosts to prevent further post-compromise behavior.
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- Review the privileges assigned to the involved users to ensure that the least privilege principle is being followed.
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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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- 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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## Config
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If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.
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"""
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risk_score = 47
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rule_id = "58aa72ca-d968-4f34-b9f7-bea51d75eb50"
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severity = "medium"
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tags = ["Elastic", "Host", "Windows", "Threat Detection", "Lateral Movement"]
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timestamp_override = "event.ingested"
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type = "eql"
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query = '''
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registry where event.type in ("creation", "change") and
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registry.path : "HKLM\\SYSTEM\\*ControlSet*\\Control\\Terminal Server\\fDenyTSConnections" and
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registry.data.strings : ("0", "0x00000000") and not (process.name : "svchost.exe" and user.domain == "NT AUTHORITY") and
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not process.executable : "C:\\Windows\\System32\\SystemPropertiesRemote.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 = "T1021"
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name = "Remote Services"
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reference = "https://attack.mitre.org/techniques/T1021/"
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[[rule.threat.technique.subtechnique]]
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id = "T1021.001"
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name = "Remote Desktop Protocol"
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reference = "https://attack.mitre.org/techniques/T1021/001/"
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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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