Detection rules › Splunk
Windows Multiple Users Fail To Authenticate Wth ExplicitCredentials
The following analytic identifies a source user failing to authenticate with 30 unique users using explicit credentials on a host. It leverages Windows Event 4648, which is generated when a process attempts an account logon by explicitly specifying account credentials. This detection is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges within an Active Directory environment. If confirmed malicious, this activity could lead to unauthorized access, privilege escalation, and potential compromise of sensitive information.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Credential Access | T1110.003 Brute Force: Password Spraying |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Security-Auditing | 4648 | A logon was attempted using explicit credentials. |
Stages and Predicates
Stage 1: search
search Caller_User_Name!="*$" EventCode=4648 Target_User_Name!="*$"
Stage 2: bucket
bucket span=5m _time
Stage 3: stats
stats dc(Target_User_Name) AS unique_accounts, … AS tried_account, … AS dest, … AS src_ip, … AS user BY _time, Computer, Caller_User_Name
Stage 4: where
where unique_accounts>30
Stage 5: search
search `macro`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Caller_User_Name | ne |
|
EventCode | eq |
|
Target_User_Name | ne |
|
unique_accounts | gt |
|