Threat Encyclopedia

TROJ_KRYPTIK

Publish date: October 09, 2012

ANALYSIS BY

Dianne Lagrimas


PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

OVERALL RISK RATING:
DAMAGE POTENTIAL:
DISTRIBUTION POTENTIAL:
REPORTED INFECTION:

  • Threat Type:Trojan

  • Destructiveness:No

  • Encrypted:

  • In the wild: Yes

OVERVIEW


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.

TECHNICAL DETAILS

File Size:

Varies

File Type:

PE

Memory Resident:

Yes

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.

SOLUTION

Minimum Scan Engine:

9.200

Trend customers:

    Keep your pattern and scan engine files updated. Trend Micro antivirus software can clean or remove most types of computer threats. Malware, though, such as Trojans, scripts, overwriting viruses and joke programs which are identified as uncleanable, should simply be deleted.

All Internet users:

    1. Use HouseCall - the Trend Micro online threat scanner to check for malware that may already be on your PC.
    2. Catch malware/grayware before they affect your PC or network. Secure your Web world with Trend Micro products that offer the best anti-threat and content security solutions for home users, corporate users, and ISPs. Go here for more information on Trend Micro products that fit your needs.


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