FormBook | Threat Level: high | Type: Infostealer

Cryptographic Identifiers

SHA256fb5bc5438cc0be0978fc6723d1f063e32b1fd5df4d3c45599e474796d5d9ab6a
MD5d531b36a45a97e1ade6ba5871cb2c5da
File Typeexe
Size1324.4 KB
First Seen2026-05-21
File NameCustom_brief_declaration_notification_for_DHL_2024sept.exe
Tagsexe, FormBook

Malware Family: FormBook

FormBook, MaaS stealer'dır.

TypeInfostealer
Programming LanguageC
Target PlatformWindows
C2 ProtocolHTTP
PurposeForm verisi hırsızlığı
First Seen Year2016
AliasesxLoader

Threat Indicators (IOC)

  • SHA256: fb5bc5438cc0be0978fc6723d1f063e32b1fd5df4d3c45599e474796d5d9ab6a
  • MD5: d531b36a45a97e1ade6ba5871cb2c5da

You can verify all hash values of this sample on VirusTotal.

System Cleanup Guide

  1. Disconnect the system from the network immediately
  2. Yeni bir cihazdan banka hesabı, sosyal medya ve e-posta şifrelerini değiştirin
  3. Move crypto wallets to a new address and abandon the old ones
  4. Start a full scan with up-to-date antivirus
  5. Clear saved browser passwords and enable 2FA
  6. Sign out of all sessions on every affected service

YARA Rule Hints

rule FormBook_SHA256 {
    meta:
        description = "FormBook sample: fb5bc5438cc0be09"
        threat_level = "high"
        first_seen = "2026-05-21"
    condition:
        hash.sha256(0, filesize) == "fb5bc5438cc0be0978fc6723d1f063e32b1fd5df4d3c45599e474796d5d9ab6a"
}

FormBook — Malware Profile

FormBook web form verisi ve credential hırsızı. SmartAssembly paketleyici. İspanyolca LATAM elektrik faturası lür.

Malware Type
Infostealer
Programming Language
C
C2 Protocol
HTTP
Target Systems
Windows
Also Known As (AKA)
xLoader

Technical Details

C dili, Windows API hooking (form grabbing), HTTP POST C2, browser form stealer, keylogger, screenshot, clipboard monitor, process injection (process hollowing)

Attribution / Threat Actor

ABD'de gelistirilmis; satis darknet forumlari uzerinden yapilmis. Dunya genelindeki multuple suc gruplarina hizmet veren MaaS platformu.

Capabilities & Behavior

Tarayıcı Kimlik Bilgileri
Çerez Hırsızlığı
Kripto Cüzdan Çalma
Sistem Bilgisi
Ekran Görüntüsü
FTP/SSH İstemci Şifreleri
E-posta İstemcisi Çalma
Veri Sızıntısı

IOC List (2 indicators)

IOC — FormBook
# SHA256 fb5bc5438cc0be0978fc6723d1f063e32b1fd5df4d3c45599e474796d5d9ab6a # MD5 d531b36a45a97e1ade6ba5871cb2c5da
TypeValueNote
sha256 fb5bc5438cc0be0978fc6723d1f063e32b1fd5df4d3c45599e474796d5d9ab6a Sample:FormBook
md5 d531b36a45a97e1ade6ba5871cb2c5da Sample:FormBook

C2 Servers (5 recorded servers for this family)

Address Type Port Protocol Status Country
45.61.136.16 ip 80 HTTP active US
hxxp://freeupgrades.net/s1xt/ domain 80 HTTP inactive US
103.75.160.239 ip 443 HTTPS inactive HK
3.29.19.86 ip — TCP inactive —
form-book.club domain 80 HTTP sinkholed —

C2 addresses are provided only from malware samples manually verified by the KEYDAL team. Commercial use is prohibited.

Tags
formbookinfostealermalwarehighsha256hash-analizi