FormBook | Threat Level: high | Type: Infostealer

Cryptographic Identifiers

SHA25686c6fd5e5fe62e44df9ad7d5aec7b7529aaa44850330a7447534a34076a38307
MD5896603cebf21d379577a9ee6b890bf36
File Typerar
Size794.8 KB
First Seen2026-05-21
File NameFirst_Invoice_sign_&_stamp.rar
TagsFormBook, rar

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: 86c6fd5e5fe62e44df9ad7d5aec7b7529aaa44850330a7447534a34076a38307
  • MD5: 896603cebf21d379577a9ee6b890bf36

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: 86c6fd5e5fe62e44"
        threat_level = "high"
        first_seen = "2026-05-21"
    condition:
        hash.sha256(0, filesize) == "86c6fd5e5fe62e44df9ad7d5aec7b7529aaa44850330a7447534a34076a38307"
}

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 86c6fd5e5fe62e44df9ad7d5aec7b7529aaa44850330a7447534a34076a38307 # MD5 896603cebf21d379577a9ee6b890bf36
TypeValueNote
sha256 86c6fd5e5fe62e44df9ad7d5aec7b7529aaa44850330a7447534a34076a38307 Sample:FormBook
md5 896603cebf21d379577a9ee6b890bf36 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