netntlm_downgrade_attack

rule netntlm_downgrade_attack {
 meta:
    author = "Florian Roth"
    description = "Detects post exploitation using NetNTLM downgrade attacks  License: https://github.com/Neo23x0/sigma/blob/master/LICENSE.Detection.Rules.md."
    reference = "https://tdm.socprime.com/tdm/info/XzZiURQ3EeoE"
    version = "0.01"
    created = "2018/03/20"
    product = "windows"
    service = "sysmon"
    mitre = "credential_access, t1212"

  events:
($selection1.metadata.product_event_type = "13" and (re.regex($selection1.target.registry.registry_key, `.*SYSTEM\\.*ControlSet.*\\Control\\Lsa\\lmcompatibilitylevel`) or re.regex($selection1.target.registry.registry_key, `.*SYSTEM\\.*ControlSet.*\\Control\\Lsa\\NtlmMinClientSec`) or re.regex($selection1.target.registry.registry_key, `.*SYSTEM\\.*ControlSet.*\\Control\\Lsa\\RestrictSendingNTLMTraffic`)))

  condition:
    $selection1
}