* [Tuning] Elastic Defend and Email Alerts Correlation
this rule uses the logs-* generic index, which causes failures on clusters without an email related integration with `destination.user.name` populated. for now limiting the rule to checkpoint email security and we can add more or users can customize it by adding more indexes.
* add checkpoint_email manifest and schema
* Update pyproject.toml
* Update multiple_alerts_email_elastic_defend_correlation.toml
* [Tuning] Windows BruteForce Rules Tuning
#1 Multiple Logon Failure from the same Source Address: converted to ES|QL and raised the threshold to 100 failed auths, alert quality should be better since it aggregates all failed auths info into one alert vs multiple EQL matches. (expected reduction more than 50%)
#2 Privileged Account Brute Force - coverted to ESQL and set the threshold to 50 in a minute. this should drop noise volume by more than 50%.
* ++
* Update execution_shell_evasion_linux_binary.toml
* Update execution_shell_evasion_linux_binary.toml
* Update defense_evasion_indirect_exec_forfiles.toml
* Update lateral_movement_remote_file_copy_hidden_share.toml
* Update lateral_movement_remote_file_copy_hidden_share.toml
* Update persistence_service_windows_service_winlog.toml
* Update credential_access_lsass_openprocess_api.toml
* Update persistence_suspicious_scheduled_task_runtime.toml
* Update impact_hosts_file_modified.toml
* Update defense_evasion_process_termination_followed_by_deletion.toml
* Update rules/windows/credential_access_lsass_openprocess_api.toml
* Update rules/windows/credential_access_bruteforce_admin_account.toml
Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
* Update rules/windows/credential_access_lsass_openprocess_api.toml
Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
* Update rules/windows/credential_access_bruteforce_multiple_logon_failure_same_srcip.toml
Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
* Update credential_access_lsass_openprocess_api.toml
* Update impact_hosts_file_modified.toml
* Update credential_access_dollar_account_relay.toml
* Update credential_access_new_terms_secretsmanager_getsecretvalue.toml
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Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
This rule is performing well in telemetry and producing alerts as expected for both explicit external account sharing and making snapshots public. Both scenarios tested.
- updated description, FP and IG
- added highlighted fields
- added `event.type` as `event_category_override` field because `event.category` is not populated for these events.
Co-authored-by: shashank-elastic <91139415+shashank-elastic@users.noreply.github.com>
This rule is performing well in telemetry, low volume and expected alerts. No major changes to rule query.
- reduced execution window
- updated description and IG
- added highlighted fields
Co-authored-by: shashank-elastic <91139415+shashank-elastic@users.noreply.github.com>
AWS S3 Bucket Replicated to Another Account
- updated description and IG
- added `event.type` as `event_category_override` field
- adjusted query to use `info` instead of `any` and added `Account=` instead of `Account` to help reduce chances of capturing unintended requests.
- added highlighted fields
AWS S3 Bucket Policy Added to Share with External Account
- added `event.outcome = success` to query to reduce noise from failed attempts
Co-authored-by: shashank-elastic <91139415+shashank-elastic@users.noreply.github.com>
* [Rule Tunings] AWS Multiple API Calls rules
AWS EC2 Multi-Region DescribeInstances API Calls
Over 2,000 alerts in the last 24 hours. This is a very noisy rule, by design it is alerting on quite normal behavior. There is not much in-the-wild threat behavior that justifies keeping this rule as a standalone alert. As a threat indicator, this is best used as a hunting rule or in correlation with another rule, for example: (GetCallerIdentity new terms + multi region DescribeInstances by same principal) or (Multiple Discovery API calls + multi region DescribeInstances by same principal) or (multi region DescribeInstances + snapshot/AMI activity by same principal). However, on its own it’s not adding much value over the noise.
- I’m keeping this as ESQL rule but converting it to a BBR
- keeping more fields for further context
- Changing investigation guide to be more relevant for hunting/correlation rule
AWS Discovery API Calls via CLI from a Single Resource
This rule is alerting as expected with low telemetry. It has to remain an ESQL rule as no other rule types can truncate the time window to 10 sec looking for a threshold of unique API calls coming from a single user.
- Keeping as ESQL rule
- Reduced execution window
- Keeping more fields for further context
- Adding highlighted fields
- Updated Investigation guide
* adding highlighted fields to keep parameter
* Apply suggestions from code review
Co-authored-by: Mika Ayenson, PhD <Mikaayenson@users.noreply.github.com>
* Apply suggestion from @imays11
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Co-authored-by: Mika Ayenson, PhD <Mikaayenson@users.noreply.github.com>
Co-authored-by: Samirbous <64742097+Samirbous@users.noreply.github.com>
Co-authored-by: Terrance DeJesus <99630311+terrancedejesus@users.noreply.github.com>
This rule is performing as expected in telemetry, low volume rare behavior. No query changes needed.
- increased the severity and risk score
- reduced execution window
- reduced lookback window for new terms
- updated description and investigation guide
- slight edits to highlighted fields
Rule is alerting as expected, with low telemetry volume. Updates to rule query are to provide more alert context as an ESQL rule.
- reduced execution window
- added additional fields for more alert context, include customer-requested `data_stream.namespace` field
- added highlighted fields
- updated description and investigation guide
* [Rule Tuning] AWS Access Token Used from Multiple Addresses
This rule is extremely loud in telemetry ~2612 alerts in last 24 hours. There have also been a couple community requests for changes.
- reduced the scope of the alerts to only surface the "high" fidelity_score cases for `"multiple_ip_network_city"` or `"multiple_ip_network_city_user_agent"` criteria. This reduced telemetry by ~90%
- excluded 2 more benign service providers `support` which reduced volume by another 6%.
- added the `data_stream.namespace` field as requested.
- kept the rest of the rule logic visible so that if customers would like to broaden the scope of this rule again, they can duplicate the rules and revert back to the broader condition `Esql.activity_type != "normal_activity"`. This has been included as a comment in the rule query.
I will keep an eye on this rule in telemetry to determine it's value moving forward.
* nit IG format changes
`CreateCluster` is a common Redshift lifecycle operation that occurs frequently in normal workflows. Creating a new Redshift cluster offers no real advantage to an attacker and outside of cost, does not produce material impact for a target environment. This behavior aligns more with cloud infrastructure monitoring or posture management, which is important but not the focus of our detection ruleset.
Real world Redshift abuse centers on misuse of existing resources, such as snapshot sharing or copying or exposing the cluster through permissive VPC security group changes. These threat paths should be covered by other rules. Deprecating this creation-focused rule reduces noise and keeps the AWS ruleset aligned with real threat surfaces rather than infrastructure management.
Samirbous