From baefaeeaffa23e942e4c1a3fa8c3f8d2f4f981ca Mon Sep 17 00:00:00 2001 From: Craig Chamberlain Date: Tue, 22 Sep 2020 16:27:17 -0400 Subject: [PATCH] [New Rule] Unusual Linux Network Connection Discovery (#266) * Create ml_linux_system_network_connection_discovery.toml ML rule to accompany the unsual network connection discovery job * Update ml_linux_system_network_connection_discovery.toml set author * Update ml_linux_system_network_connection_discovery.toml added fasle positve field * Update ml_linux_system_network_connection_discovery.toml * Update ml_linux_system_network_connection_discovery.toml linting * Update rules/ml/ml_linux_system_network_connection_discovery.toml Co-authored-by: Justin Ibarra * Update ml_linux_system_network_connection_discovery.toml Co-authored-by: Justin Ibarra --- ...x_system_network_connection_discovery.toml | 43 +++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 rules/ml/ml_linux_system_network_connection_discovery.toml diff --git a/rules/ml/ml_linux_system_network_connection_discovery.toml b/rules/ml/ml_linux_system_network_connection_discovery.toml new file mode 100644 index 000000000..80f33bccb --- /dev/null +++ b/rules/ml/ml_linux_system_network_connection_discovery.toml @@ -0,0 +1,43 @@ +[metadata] +creation_date = "2020/09/03" +ecs_version = ["1.6.0"] +maturity = "production" +updated_date = "2020/09/03" + +[rule] +anomaly_threshold = 25 +author = ["Elastic"] +description = """ +Looks for commands related to system network connection discovery from an unusual user context. This can be due to +uncommon troubleshooting activity or due to a compromised account. A compromised account may be used by a threat actor +to engage in system network connection discovery in order to increase their understanding of connected services and +systems. This information may be used to shape follow-up behaviors such as lateral movement or additional discovery. +""" +false_positives = [ + """ + Uncommon user command activity can be due to an engineer logging onto a server instance in order to perform manual + troubleshooting or reconfiguration. + """, +] +from = "now-45m" +interval = "15m" +license = "Elastic License" +machine_learning_job_id = "linux_network_connection_discovery" +name = "Unusual Linux Network Connection Discovery" +risk_score = 21 +rule_id = "c28c4d8c-f014-40ef-88b6-79a1d67cd499" +severity = "low" +tags = ["Elastic", "Linux", "ML"] +type = "machine_learning" +[[rule.threat]] +framework = "MITRE ATT&CK" +[[rule.threat.technique]] +id = "T1049" +name = "System Network Connections Discovery" +reference = "https://attack.mitre.org/techniques/T1049/" + + +[rule.threat.tactic] +id = "TA0007" +name = "Discovery" +reference = "https://attack.mitre.org/tactics/TA0007/"