BlueSky Ransomware Artefacts

 1title: BlueSky Ransomware Artefacts
 2id: eee8311f-a752-44f0-bf2f-6b007db16300
 3status: test
 4description: Detect access to files and shares with names and extensions used by BlueSky ransomware which could indicate a current or previous encryption attempt.
 5references:
 6    - https://unit42.paloaltonetworks.com/bluesky-ransomware/
 7author: j4son
 8date: 2023/05/23
 9tags:
10    - attack.impact
11    - attack.t1486
12    - detection.emerging_threats
13logsource:
14    product: windows
15    service: security
16detection:
17    selection_access_eid:
18        EventID:
19            - 4663
20            - 4656
21    selection_access_data:
22        - ObjectName|endswith: '.bluesky'
23        - ObjectName|contains: 'DECRYPT FILES BLUESKY'
24    selection_share_eid:
25        EventID: 5145
26    selection_share_data:
27        - RelativeTargetName|endswith: '.bluesky'
28        - RelativeTargetName|contains: 'DECRYPT FILES BLUESKY'
29    condition: all of selection_access_* or all of selection_share_*
30falsepositives:
31    - Unknown
32level: high