FormBook | Threat Level: high | Type: Infostealer

Cryptographic Identifiers

SHA25643a1dac3d7b5719c790f07cc02f4fbf5b4513f4498a2afbafa66d0450b311938
MD562e8b5cec6b748bbd0be757bd4fda660
File Type7z
Size498.8 KB
First Seen2026-05-21
File NameEX777915904751.PDF.7z
Tags7z, 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: 43a1dac3d7b5719c790f07cc02f4fbf5b4513f4498a2afbafa66d0450b311938
  • MD5: 62e8b5cec6b748bbd0be757bd4fda660

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: 43a1dac3d7b5719c"
        threat_level = "high"
        first_seen = "2026-05-21"
    condition:
        hash.sha256(0, filesize) == "43a1dac3d7b5719c790f07cc02f4fbf5b4513f4498a2afbafa66d0450b311938"
}

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 43a1dac3d7b5719c790f07cc02f4fbf5b4513f4498a2afbafa66d0450b311938 # MD5 62e8b5cec6b748bbd0be757bd4fda660
TypeValueNote
sha256 43a1dac3d7b5719c790f07cc02f4fbf5b4513f4498a2afbafa66d0450b311938 Sample:FormBook
md5 62e8b5cec6b748bbd0be757bd4fda660 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