Suspicious Rundll32 Execution of UDL File

 1title: Suspicious Rundll32 Execution of UDL File
 2id: 0ea52357-cd59-4340-9981-c46c7e900428
 3status: experimental
 4description: Detects the execution of rundll32.exe with the oledb32.dll library to open a UDL file. Threat actors can abuse the technique as a phishing vector to capture authentication credentials or other sensitive data.
 5author: '@kostastsale'
 6date: 2024-08-16
 7references:
 8    - https://trustedsec.com/blog/oops-i-udld-it-again
 9tags:
10    - attack.execution
11    - attack.t1218.011
12    - attack.t1071
13logsource:
14    category: process_creation
15    product: windows
16detection:
17    selection1:
18        ParentImage|endswith:
19            - '\explorer.exe'
20        Image|endswith:
21            - '\rundll32.exe'
22        CommandLine|contains|all:
23            - 'oledb32.dll'
24            - ',OpenDSLFile '
25            - '\\Users\\*\\Downloads\\' # you can adjust the path to the download directory or other directories accroding to your environment
26    selection2:
27        CommandLine|endswith:
28            - '.udl'
29    condition: selection1 and selection2
30falsepositives:
31    - UDL files serve as a convenient and flexible tool for managing and testing database connections in various development and administrative scenarios
32level: medium