W32/Sober.C@mm

description-logoAnalysis

  • Virus is 32bit and has a compressed file size of 73,728 bytes
  • Virus was coded using Visual Basic 6
  • The virus is introduced to the system as an email attachment
  • The virus will write a copy of itself into the undefinedWindowsundefined\System32 folder as several possible file names, and then modify the registry to load at Windows startup as in this example -

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Currentversion\Run\
    (value) = C:\WINNT\System32\syshostx.exe

    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\
    (value) = C:\WINNT\System32\syshostx.exe

  • The virus will then scavenge the hard drive looking for email addresses - the virus looks inside files with the following extensions -

    .abc
    .ade
    .adp
    .asp
    .cfg
    .dbx
    .doc
    .dsp
    .dsw
    .eml
    .fdb
    .hlp
    .htm
    .html
    .htt
    .ini
    .ldb
    .ldif
    .mda
    .mdb
    .mde
    .mdw
    .mht
    .nab
    .nfo
    .nsf
    .php
    .pst
    .rtf
    .shtm
    .shtml
    .sln
    .txt
    .vap
    .wab
    .xls

  • The virus will write a file "savesyss.dll" to undefinedWindowsundefined\System32 - savesyss.dll will contain all of the email addresses found on the system

  • The virus will then use SMTP code to send randomly formatted email messages to recipients in the list from savesyss.dll - the subject lines and body text will be varied, and the attachment file name will also be chosen at random from a list

  • The email subject and body text may be either English or German

  • Some of the following file names are used in an attempt to trick the recipient into thinking the file attachment is a web site link -

    www.anime4allfree.com
    www.animepage43252.com
    www.boards4all-terror432.com
    www.free4manga.com
    www.free4share4you.com
    www.freegames4you-gzone.com
    www.freewantiv.com
    www.iq4you-german-test.com
    www.onlinegamerspro-worm.com
    www.tagespolitik-umfragen.com


recommended-action-logoRecommended Action

  • Check the main screen using the web interface for your FortiGate unit to ensure that the latest AV/NIDS database has been downloaded and installed on your system - if required, enable the "Allow Push Update" option
  • Alternatively, this virus can be blocked by FortiGate units by enabling blocking of file attachments with ZIP, .COM, .EXE, .BAT, .PIF or .SCR extensions; using the FortiGate manager, enable blocking of these extensions using SMTP, IMAP or POP3 services

Telemetry logoTelemetry

Detection Availability

FortiGate
Extreme
FortiClient
Extended
FortiMail
Extended
FortiSandbox
Extended
FortiWeb
Extended
Web Application Firewall
Extended
FortiIsolator
Extended
FortiDeceptor
Extended
FortiEDR

Version Updates

Date Version Detail
2024-01-01 92.00251
2023-11-16 91.08855
2022-07-19 90.04286
2022-01-11 89.08602
2019-09-05 71.39200 Sig Updated
2019-07-29 70.33600 Sig Added