Suspicious File Download From File Sharing Domain Via Curl.EXE

Severity: high
Author: Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects potentially suspicious file download from file sharing domains using curl.exe

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_img`

or:
Image|endswith: '\curl.exe'
OriginalFileName: curl.exe

Stage 2: `all of selection_websites`

or:
CommandLine|contains: .githubusercontent.com
CommandLine|contains: anonfiles.com
CommandLine|contains: cdn.discordapp.com
CommandLine|contains: ddns.net
CommandLine|contains: dl.dropboxusercontent.com
CommandLine|contains: ghostbin.co
CommandLine|contains: github.com
CommandLine|contains: glitch.me
CommandLine|contains: gofile.io
CommandLine|contains: hastebin.com
CommandLine|contains: mediafire.com
CommandLine|contains: mega.nz
CommandLine|contains: onrender.com
CommandLine|contains: pages.dev
CommandLine|contains: paste.ee
CommandLine|contains: pastebin.com
CommandLine|contains: pastebin.pl
CommandLine|contains: pastetext.net
CommandLine|contains: pixeldrain.com
CommandLine|contains: privatlab.com
CommandLine|contains: privatlab.net
CommandLine|contains: send.exploit.in
CommandLine|contains: sendspace.com
CommandLine|contains: storage.googleapis.com
CommandLine|contains: storjshare.io
CommandLine|contains: supabase.co
CommandLine|contains: temp.sh
CommandLine|contains: transfer.sh
CommandLine|contains: trycloudflare.com
CommandLine|contains: ufile.io
CommandLine|contains: w3spaces.com
CommandLine|contains: workers.dev

Stage 3: `all of selection_http`

CommandLine|contains: http

Stage 4: `all of selection_flag`

or:
CommandLine|contains: ' -O'
CommandLine|contains: --output
CommandLine|contains: --remote-name

Stage 5: `all of selection_ext`

or:
CommandLine|endswith: .bat
CommandLine|endswith: '.bat'''
CommandLine|endswith: '.bat"'
CommandLine|endswith: .dat
CommandLine|endswith: '.dat'''
CommandLine|endswith: '.dat"'
CommandLine|endswith: .dll
CommandLine|endswith: '.dll'''
CommandLine|endswith: '.dll"'
CommandLine|endswith: .exe
CommandLine|endswith: '.exe'''
CommandLine|endswith: '.exe"'
CommandLine|endswith: .hta
CommandLine|endswith: '.hta'''
CommandLine|endswith: '.hta"'
CommandLine|endswith: .msi
CommandLine|endswith: '.msi'''
CommandLine|endswith: '.msi"'
CommandLine|endswith: .ps1
CommandLine|endswith: '.ps1'''
CommandLine|endswith: '.ps1"'
CommandLine|endswith: .psm1
CommandLine|endswith: '.psm1'''
CommandLine|endswith: '.psm1"'
CommandLine|endswith: .vbe
CommandLine|endswith: '.vbe'''
CommandLine|endswith: '.vbe"'
CommandLine|endswith: .vbs
CommandLine|endswith: '.vbs'''
CommandLine|endswith: '.vbs"'

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
`CommandLine`	ends_with	`.bat` corpus 5 (sigma 5) `.bat"` corpus 5 (sigma 5) `.bat'` corpus 5 (sigma 5) `.dat` corpus 7 (sigma 7) `.dat"` corpus 5 (sigma 5) `.dat'` corpus 5 (sigma 5) `.dll` corpus 9 (sigma 9) `.dll"` corpus 6 (sigma 6) `.dll'` corpus 6 (sigma 6) `.exe` corpus 6 (sigma 6) `.exe"` corpus 5 (sigma 5) `.exe'` corpus 5 (sigma 5) `.hta` corpus 6 (sigma 6) `.hta"` corpus 5 (sigma 5) `.hta'` corpus 5 (sigma 5) `.msi` corpus 5 (sigma 5) `.msi"` corpus 5 (sigma 5) `.msi'` corpus 5 (sigma 5) `.ps1` corpus 6 (sigma 6) `.ps1"` corpus 5 (sigma 5) `.ps1'` corpus 5 (sigma 5) `.psm1` corpus 6 (sigma 6) `.psm1"` corpus 5 (sigma 5) `.psm1'` corpus 5 (sigma 5) `.vbe` corpus 7 (sigma 7) `.vbe"` corpus 5 (sigma 5) `.vbe'` corpus 5 (sigma 5) `.vbs` corpus 7 (sigma 7) `.vbs"` corpus 5 (sigma 5) `.vbs'` corpus 5 (sigma 5)
`CommandLine`	match	`-O` corpus 3 (sigma 3) `--output` corpus 3 (sigma 3) `--remote-name` corpus 3 (sigma 3) `.githubusercontent.com` corpus 4 (sigma 4) `anonfiles.com` corpus 5 (sigma 5) `cdn.discordapp.com` corpus 5 (sigma 5) `ddns.net` corpus 5 (sigma 5) `dl.dropboxusercontent.com` corpus 5 (sigma 5) `ghostbin.co` corpus 5 (sigma 5) `github.com` corpus 4 (sigma 4) `glitch.me` corpus 5 (sigma 5) `gofile.io` corpus 5 (sigma 5) `hastebin.com` corpus 5 (sigma 5) `http` corpus 31 (sigma 31) `mediafire.com` corpus 5 (sigma 5) `mega.nz` corpus 5 (sigma 5) `onrender.com` corpus 5 (sigma 5) `pages.dev` corpus 5 (sigma 5) `paste.ee` corpus 5 (sigma 5) `pastebin.com` corpus 5 (sigma 5) `pastebin.pl` corpus 5 (sigma 5) `pastetext.net` corpus 5 (sigma 5) `pixeldrain.com` corpus 3 (sigma 3) `privatlab.com` corpus 5 (sigma 5) `privatlab.net` corpus 5 (sigma 5) `send.exploit.in` corpus 5 (sigma 5) `sendspace.com` corpus 5 (sigma 5) `storage.googleapis.com` corpus 5 (sigma 5) `storjshare.io` corpus 5 (sigma 5) `supabase.co` corpus 5 (sigma 5) `temp.sh` corpus 5 (sigma 5) `transfer.sh` corpus 5 (sigma 5) `trycloudflare.com` corpus 5 (sigma 5) `ufile.io` corpus 5 (sigma 5) `w3spaces.com` corpus 5 (sigma 5) `workers.dev` corpus 5 (sigma 5)
`Image`	ends_with	`\curl.exe` corpus 19 (sigma 19)
`OriginalFileName`	eq	`curl.exe` corpus 11 (sigma 11)

Suspicious File Download From File Sharing Domain Via Curl.EXE

Event coverage

Stages and Predicates

Stage 1: all of selection_img

Stage 2: all of selection_websites

Stage 3: all of selection_http