FormBook | Threat Level: high | Type: Infostealer

Cryptographic Identifiers

SHA256671c99fe3edc789c6f5995507a8745a1e0137e03346f31ffbe4092289931631d
MD54e1b1941ffee9c47595882bc50aecb4f
File Typejs
Size2996.2 KB
First Seen2026-06-11
File NameSwift_USD.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: 671c99fe3edc789c6f5995507a8745a1e0137e03346f31ffbe4092289931631d
  • MD5: 4e1b1941ffee9c47595882bc50aecb4f

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: 671c99fe3edc789c"
        threat_level = "high"
        first_seen = "2026-06-11"
    condition:
        hash.sha256(0, filesize) == "671c99fe3edc789c6f5995507a8745a1e0137e03346f31ffbe4092289931631d"
}

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 671c99fe3edc789c6f5995507a8745a1e0137e03346f31ffbe4092289931631d # MD5 4e1b1941ffee9c47595882bc50aecb4f
TypeValueNote
sha256 671c99fe3edc789c6f5995507a8745a1e0137e03346f31ffbe4092289931631d Sample:FormBook
md5 4e1b1941ffee9c47595882bc50aecb4f 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