Detection rules › Sigma

Suspicious File Downloaded From File-Sharing Website Via Certutil.EXE

Severity
high
Author
Nasreddine Bencherchali (Nextron Systems)
Source
upstream

Detects the execution of certutil with certain flags that allow the utility to download files from file-sharing websites.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1027 Obfuscated Files or Information
Command & ControlT1105 Ingress Tool Transfer

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation

Stages and Predicates

Stage 1: all of selection_img

or:
Image|endswith: '\certutil.exe'
OriginalFileName: CertUtil.exe

Stage 2: all of selection_flags

or:
CommandLine|contains: 'URL '
CommandLine|contains: 'urlcache '
CommandLine|contains: 'verifyctl '

Stage 3: all of selection_http

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: 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

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.

FieldKindValues
CommandLinematch
  • .githubusercontent.com corpus 4 (sigma 4)
  • URL corpus 3 (sigma 3)
  • 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)
  • 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)
  • 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)
  • urlcache corpus 3 (sigma 3)
  • verifyctl corpus 3 (sigma 3)
  • w3spaces.com corpus 5 (sigma 5)
  • workers.dev corpus 5 (sigma 5)
Imageends_with
  • \certutil.exe corpus 34 (sigma 34)
OriginalFileNameeq
  • CertUtil.exe corpus 13 (sigma 13)