TROJ_KRYPTIK

This description is based is a compiled analysis of several variants of TROJ_KRYPTIK. Note that specific data such as file names and registry values may vary for each variant.

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives as a file that exports the functions of other malware/grayware. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It arrives as a component bundled with malware/grayware packages.

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It arrives as a file that exports the functions of other malware/grayware.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It arrives as a component bundled with malware/grayware packages.

Installation

This Trojan drops the following copies of itself into the affected system:

• {malware path}\{malware file name}

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random name} = "{malware path}\{malware file name}"

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and file name} = "{malware path and file name}.exe:*:Enabled:ldrsoft"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Download
CheckExeSignatures = "no"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
DisableTaskMgr = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Attachments
SaveZoneInformation = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Associations
LowRiskFileTypes = ".zip;.rar;.nfo;.txt;.exe;.bat;.com;.cmd;.reg;.msi;.htm;.html;.gif;.bmp;.jpg;.avi;.mpg;.mpeg;.mov;.mp3;.m3u;.wav;.scr;"

Rogue Antivirus Routine

This Trojan displays the following fake alerts:

• Failed to read system files configuration. Start a system diagnostics application to scan your hard disk for errors and performance problems.
• A performance problem with one or more installed IDE / SATA hard drives has been detected. System restart is highly recommended.
• Un error ocurrio durante la lectura de los ficheros del sistema. Ejecute la utilidad diagnostica del sistema para chequear su unidad del disco duro para errores.
• El sistema ha detectado un problema con uno o mas IDE / SATA discos duros instalados. Vd. esta aconsejado a reiniciar el sistema.
• Ein Fehler beim Lesen Systemdateien eingetreten. Fuhren Sie ein Diagnoseprogramm fur Fehlerbestimmung durch.
• Das System hat ein Problem mit einem oder mehreren installierten IDE / SATA-Festplatten erkannt. Es wird empfohlen, das System neu zu starten.
• Errore durante la lettura di file di sistema Lanciate l'utilita di diagnostica del sistema per verificare il hard disk per gli errori.
• Il sistema ha rilevato un problema con uno o pi? hard disk IDE / SATA istallati. Si raccomanda di riaccendere il sistema.
• utilitaire de diagnostique du systeme pour detecter les erreurs sur votre disque dur.
• Le systeme a detecte un probleme avec un ou plusieurs disques durs IDE / SATA installes. Nous vous recommandons de redemarrer votre systeme.
• Sistem dosyalar? okuma s?ras?nda hata olusmustur. Sistem tan?mlama yard?mc? program?n? sabit disk surucusunu kontrol etmek icin baslay?n.
• Sistem yuklenmis bir veya fazlas? olan IDE / SATA sabit disklerde hatay? tespit etti. Sisteminizi yeniden baslatman?z tavsiye edilir.

NOTES:

This description is based is a compiled analysis of several variants of TROJ_KRYPTIK. Note that specific data such as file names and registry values may vary for each variant.