PH_Rule_SIGMA_1265
Enabled
Detects potential use of UIPromptForCredentials functions by looking for some of the DLLs needed for it. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/image_load/image_load_uipromptforcreds_dlls.yml
5
Security
Collection
Collection consists of techniques adversaries may use to gather information and the sources information is collected from that are relevant to following through on the adversary's objectives. Frequently, the next goal after collecting data is to steal (exfiltrate) the data. Common target sources include various drive types, browsers, audio, video, and email. Common collection methods include capturing screenshots and keyboard input.
https://attack.mitre.org/tactics/TA0009T1056.002
Input Capture: GUI Input Capture
Adversaries may mimic common operating system GUI components to prompt users for credentials with a seemingly legitimate prompt. When programs are executed that need additional privileges than are present in the current user context, it is common for the operating system to prompt the user for proper credentials to authorize the elevated privileges for the task. Adversaries may mimic this functionality to prompt users for credentials with a seemingly legitimate prompt for a number of reasons that mimic normal usage, such as a fake installer requiring additional access or a fake malware removal suite.
https://attack.mitre.org/techniques/T1056/002Server
Windows Sysmon via FortiSIEM Agent
Correlation
No remediation guidance specified
If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.
300 seconds
If the following defined pattern/s occur within a 300 second time window.
Filter
This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.
This is the query logic that matches incoming events
eventType="Win-Sysmon-7-Image-Loaded" AND (loadedProcName REGEXP "\\credui\.dll$|\\wincredui\.dll$" OR srcFileName IN ("credui.dll","wincredui.dll")) AND ((procName NOT REGEXP "^C:\\Program Files \(x86\)\\|^C:\\Program Files\\|^C:\\Windows\\SysWOW64\\|^C:\\Windows\\System32\\") AND (procName NOT REGEXP "\\opera_autoupdate\.exe$|\\procexp64\.exe$|\\procexp\.exe$") AND (procName NOT IN ("C:\\Windows\\ImmersiveControlPanel\\SystemSettings.exe","C:\\Windows\\explorer.exe")) AND (procName NOT REGEXP "^C:\\Users\\" OR procName NOT REGEXP "\\AppData\\Local\\Microsoft\\Teams\\current\\Teams\.exe$|\\AppData\\Local\\Microsoft\\Teams\\stage\\Teams\.exe$|\\AppData\\Roaming\\Spotify\\Spotify\.exe$") AND (procName NOT REGEXP "^C:\\Users\\" OR procName NOT REGEXP ".*\\AppData\\Local\\Microsoft\\OneDrive\\.*") AND (procName!="C:\\Windows\\regedit.exe") AND (command NOT REGEXP ".*C:\\Program Files\\WindowsApps\\SpotifyAB\.SpotifyMusic_.*"))
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
command,hostName,loadedProcName,procName,srcFileName
This is most typically a numerical constraint that defines when the rule should trigger an incident
COUNT(*) >= 1
This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.
The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern
command = Filter.command,
hostName = Filter.hostName,
loadedProcName = Filter.loadedProcName,
procName = Filter.procName,
srcFileName = Filter.srcFileName