Suspicious File Download From IP Via Curl.EXE

Detects potentially suspicious file downloads directly from IP addresses using curl.exe

Sigma rule (View on GitHub)

 1title: Suspicious File Download From IP Via Curl.EXE
 2id: 5cb299fc-5fb1-4d07-b989-0644c68b6043
 3status: test
 4description: Detects potentially suspicious file downloads directly from IP addresses using curl.exe
 5references:
 6    - https://labs.withsecure.com/publications/fin7-target-veeam-servers
 7    - https://github.com/WithSecureLabs/iocs/blob/344203de742bb7e68bd56618f66d34be95a9f9fc/FIN7VEEAM/iocs.csv
 8    - https://github.com/pr0xylife/IcedID/blob/8dd1e218460db4f750d955b4c65b2f918a1db906/icedID_09.28.2023.txt
 9author: Nasreddine Bencherchali (Nextron Systems)
10date: 2023-07-27
11tags:
12    - attack.execution
13logsource:
14    category: process_creation
15    product: windows
16detection:
17    selection_img:
18        - Image|endswith: '\curl.exe'
19        - OriginalFileName: 'curl.exe'
20    selection_ip:
21        CommandLine|re: '://[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'
22    selection_http:
23        CommandLine|contains: 'http'
24    selection_flag:
25        CommandLine|contains:
26            - ' -O'  # covers the alias for --remote-name and --output
27            - '--remote-name'
28            - '--output'
29    selection_ext:
30        # Note: If you add more extensions please consider adding them also in 9cc85849-3b02-4cb5-b371-3a1ff54f2218
31        CommandLine|endswith:
32            - '.bat'
33            - '.bat"'
34            - '.dat'
35            - '.dat"'
36            - '.dll'
37            - '.dll"'
38            - '.exe'
39            - '.exe"'
40            - '.gif'
41            - '.gif"'
42            - '.hta'
43            - '.hta"'
44            - '.jpeg'
45            - '.jpeg"'
46            - '.log'
47            - '.log"'
48            - '.msi'
49            - '.msi"'
50            - '.png'
51            - '.png"'
52            - '.ps1'
53            - '.ps1"'
54            - '.psm1'
55            - '.psm1"'
56            - '.vbe'
57            - '.vbe"'
58            - '.vbs'
59            - '.vbs"'
60            - ".bat'"
61            - ".dat'"
62            - ".dll'"
63            - ".exe'"
64            - ".gif'"
65            - ".hta'"
66            - ".jpeg'"
67            - ".log'"
68            - ".msi'"
69            - ".png'"
70            - ".ps1'"
71            - ".psm1'"
72            - ".vbe'"
73            - ".vbs'"
74    condition: all of selection_*
75falsepositives:
76    - Unknown
77level: high

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