FormBook | Threat Level: high | Type: Infostealer

Cryptographic Identifiers

SHA256cb70357549841be383d38d9c155e6cb95b46c1711f7e67c8a2274d1166a3a538
MD536079f78a7ee64959cbb57304d5b5dd9
File Typeexe
Size1083.0 KB
First Seen2026-05-08
File Namecb70357549841be383d38d9c155e6cb95b46c1711f7e67c8a2274d1166a3a538
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: cb70357549841be383d38d9c155e6cb95b46c1711f7e67c8a2274d1166a3a538
  • MD5: 36079f78a7ee64959cbb57304d5b5dd9

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: cb70357549841be3"
        threat_level = "high"
        first_seen = "2026-05-08"
    condition:
        hash.sha256(0, filesize) == "cb70357549841be383d38d9c155e6cb95b46c1711f7e67c8a2274d1166a3a538"
}

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 cb70357549841be383d38d9c155e6cb95b46c1711f7e67c8a2274d1166a3a538 # MD5 36079f78a7ee64959cbb57304d5b5dd9
TypeValueNote
sha256 cb70357549841be383d38d9c155e6cb95b46c1711f7e67c8a2274d1166a3a538 Sample:FormBook
md5 36079f78a7ee64959cbb57304d5b5dd9 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