FormBook | Threat Level: high | Type: Infostealer

Cryptographic Identifiers

SHA2563d5866fc83f0bba01201b68888a75827195ec55978d19ca99e6f602a1adf8f0a
MD549f273b1c605d717495ed437fbd3b5ef
File Typejs
Size31.8 KB
First Seen2026-06-18
File NameRFQ Specification.js
TagsFormBook, js

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: 3d5866fc83f0bba01201b68888a75827195ec55978d19ca99e6f602a1adf8f0a
  • MD5: 49f273b1c605d717495ed437fbd3b5ef

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: 3d5866fc83f0bba0"
        threat_level = "high"
        first_seen = "2026-06-18"
    condition:
        hash.sha256(0, filesize) == "3d5866fc83f0bba01201b68888a75827195ec55978d19ca99e6f602a1adf8f0a"
}

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 3d5866fc83f0bba01201b68888a75827195ec55978d19ca99e6f602a1adf8f0a # MD5 49f273b1c605d717495ed437fbd3b5ef
TypeValueNote
sha256 3d5866fc83f0bba01201b68888a75827195ec55978d19ca99e6f602a1adf8f0a Sample:FormBook
md5 49f273b1c605d717495ed437fbd3b5ef 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