Threat Description

Email-Worm:​W32/Sober.P

Details

Aliases:Email-Worm.Win32.Sober.p
Category:Malware
Type:Email-Worm
Platform:W32

Summary



A worm that spreads via e-mail, usually in infected executable e-mail file attachments.



Removal



F-Secure provides a simple disinfection utility to eliminate Sober.P worm infection. You can download this utility from our ftp site:

  • ftp://ftp.europe.f-secure.com/anti-virus/tools/sober_p_disinfect.zip
  • ftp://ftp.europe.f-secure.com/anti-virus/tools/sober_p_disinfect.bat (unpacked version)

Disinfection instructions can be found here:

  • ftp://ftp.europe.f-secure.com/anti-virus/tools/sober_p_disinfect.txt


Technical Details



Email-Worm:W32/Sober.P was found on May 2nd, 2005. It sends itself as an attachment in e-mail messages with English or German texts. The worm is written in Visual Basic, UPX-packed PE executable about 52 kilobytes long. The worm sends different types of e-mail messages with English and German texts and an attachment. The attachment is a ZIP archive containing the worm's executable. Update on May 13th, 2005 - since Sober.P worm stopped its spreading, we are downgrading its Radar level.

Installation

Once run, it will display a decoy error message:

It will then drop three new files "services.exe", "csrss.exe" and "smss.exe" into the %WinDir%\Connection Wizard\Status\ folder, created by the worm. All dropped files are closely related to the original worm's binary. Sober.P worm adds startup keys for "services.exe" in System Registry:

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run " WinStart" %WinDir%\Connection Wizard\Status\services.exe

Upon reboot, this file will start the other two executable files. The worm also creates several files in its installation directory:

  • packed1.sbr
  • packed2.sbr
  • packed3.sbr

These files contain BASE64-encoded representation of the Worm's body. These files are used later when sending e-mail messages.

Payload

Sober.P monitors a fixed list of NTP servers to syncronize its time. It the date is 27.4.2005 or later, it tries to download and execute file from one of the following domains:

  • free.pages.at
  • home.arcor.de
  • people.freenet.de
  • scifi.pages.at
  • home.pages.at

The following list of NTP servers are checked:

  • Rolex.PeachNet.edu
  • cuckoo.nevada.edu
  • ntp-1.ece.cmu.edu
  • ntp-sop.inria.fr
  • ntp.lth.se
  • ntp.massayonet.com.br
  • ntp.metas.ch
  • ntp.pads.ufrj.br
  • ntp1.arnes.si
  • ntp3.fau.de
  • rolex.usg.edu
  • sundial.columbia.edu
  • time-a.timefreq.bldrdoc.gov
  • time-ext.missouri.edu
  • time-server.ndo.com
  • time.kfki.hu
  • time.nist.gov
  • time.xmission.com
  • timelord.uregina.ca
  • utcnist.colorado.edu

Sober.P checks for its network connection using 'RasEnumConnections' win32 API call. If not successful, it tries to connect to several domains using TCP port 80. The worm also queries the following list of DNS servers:

  • 165.230.99.71
  • 8.10.3.56
  • 128.135.5.5
  • 202.89.131.4
  • 219.127.89.34
  • 129.115.102.150
  • 38.9.211.2
  • 134.94.80.2
  • 130.149.2.12
  • 150.203.22.28
  • 131.215.254.100
  • 128.194.254.2
  • 4.2.2.3
  • 195.185.185.195
  • 209.68.2.46
  • 129.186.1.200
  • 198.6.1.2
  • 131.243.64.3
  • 24.93.40.33
  • 195.182.96.29
  • 192.90.162.8
  • 158.43.128.1
  • 128.35.253.3
  • 61.95.134.168
  • 200.74.214.246
  • 204.117.214.10
  • 194.25.2.129
  • 203.162.0.11
  • 210.66.241.1
  • 217.237.150.225
  • 217.237.151.161
  • 128.9.128.127
  • 151.201.0.39
  • 209.253.113.2
  • 213.239.234.108
  • 62.156.146.242
  • 207.69.188.186
  • 207.217.120.43
  • 129.187.10.25
  • 200.52.83.103
  • 129.187.16.1
  • 141.40.10.35
  • 213.218.170.6
  • 212.242.88.2
  • 193.158.124.143

One of the following domains are queried from the DNS servers:

  • microsoft.com
  • bigfoot.com
  • yahoo.com
  • t-online.de
  • google.com
  • hotmail.com

Propagation (E-mail)

The worm sends different types of e-mail messages with English or German texts and its file attached. The attachment is a ZIP archive containing the worm's executable. Before spreading the worm scans files with certain extensions on all hard disks to harvest e-mail addresses. Files with the following extensions are scanned:

  • pmr
  • phtm
  • stm
  • slk
  • inbox
  • imb
  • csv
  • bak
  • imh
  • xhtml
  • imm
  • imh
  • cms
  • nws
  • vcf
  • ctl
  • dhtm
  • cgi
  • pp
  • ppt
  • msg
  • jsp
  • oft
  • vbs
  • uin
  • ldb
  • abc
  • pst
  • cfg
  • mdw
  • mbx
  • mdx
  • mda
  • adp
  • nab
  • fdb
  • vap
  • dsp
  • ade
  • sln
  • dsw
  • mde
  • frm
  • bas
  • adr
  • cls
  • ini
  • ldif
  • log
  • mdb
  • xml
  • wsh
  • tbb
  • abx
  • abd
  • adb
  • pl
  • rtf
  • mmf
  • doc
  • ods
  • nch
  • xls
  • nsf
  • txt
  • wab
  • eml
  • hlp
  • mht
  • nfo
  • php
  • asp
  • shtml
  • dbx

While harvesting for e-mail addresses, if one of the following substrings is present:

  • ntp-
  • ntp@
  • ntp.
  • info@
  • test@
  • @www
  • @from.
  • support
  • smtp-
  • @smtp.
  • gold-certs
  • ftp.
  • .dial.
  • .ppp.
  • anyone
  • subscribe
  • announce
  • @gmetref
  • sql.
  • someone
  • nothing
  • you@
  • user@
  • reciver@
  • somebody
  • secure
  • whatever@
  • whoever@
  • anywhere
  • yourname
  • mustermann@
  • .kundenserver.
  • mailer-daemon
  • variabel
  • noreply
  • -dav
  • law2
  • .sul.t-
  • .qmail@
  • t-ipconnect
  • t-dialin
  • ipt.aol
  • time
  • freeav
  • @ca.
  • abuse
  • winrar
  • domain.
  • host.
  • viren
  • bitdefender
  • spybot
  • detection
  • ewido.
  • emsisoft
  • linux
  • google
  • @foo.
  • winzip
  • @example.
  • bellcore.
  • @arin
  • mozilla
  • iana@
  • iana-
  • @iana
  • @avp
  • icrosoft.
  • @sophos
  • @panda
  • @kaspers
  • free-av
  • antivir
  • virus
  • verizon.
  • @ikarus.
  • @nai.
  • @messagelab
  • nlpmail01.
  • clock

then the e-mail address collected is discarded. Depending on the domain the e-message message is being designated to, either English or German language will be used. Usually domains such as: .de, gmx.de, gmx.at, gmx.net, gmx.ch will receive messages constructed in German language. Example messages may have subjects:

  • Re: Your Password
  • Re: Registration Confirmation
  • Re: Your email was blocked
  • Re: mailing error
  • FwD: Ihr Passwort
  • FwD: Ihre E-Mail wurde verweigert
  • FwD: Ich bin's, was zum lachen ;)
  • FwD: Glueckwunsch: Ihr WM Ticket
  • FwD: WM Ticket Verlosung
  • FwD: WM-Ticket-Auslosung

and body texts: Account and Password Information are attached! Visit: http://www.[collected_url].com This is an automatically generated E-Mail Delivery Status Notification.Mail-Header, Mail-Body and Error Description are attachedAttachment-Scanner: Status OK,AntiVirus: No Virus found,Server-AntiVirus: No Virus (Clean) Passwort und Benutzer-Informationen befinden sich in der beigefuegten Anlage. *-* http://www.[collected_url]*-* MailTo: PasswordHelp@[collected_url] **** AntiVirus: Kein Virus gefunden **** "GMX" AntiVirus Service **** WebSite: http://www.gmx.de Attachments:

  • mail_info.zip
  • our_secret.zip
  • Fifa_Info-Text.zip
  • okTicket-info.zip
  • free_PassWort-Info.zip
  • LOL.zip

One example of a mail Sober.P might send is a German message promising free tickets to the soccer world championships:

Herzlichen Glueckwunsch,
beim Run auf die begehrten Tickets fr die 64 Spiele der Weltmeisterschaft 2006 in Deutschland sind Siedabei.
Weitere Details ihrer Daten entnehmen Sie bitte dem Anhang.
St. Rainer Gellhaus
--- Pressesprecher Jens Grittner und Gerd Graus
--- FIFA Fussball-Weltmeisterschaft 2006
--- Organisationskomitee Deutschland
--- Tel. 069 / 2006 - 2600
--- Jens.Grittner@ok2006.de--- Gerd.Graus@ok2006.de


Detection


Sober.P is detected with the following FSAV update:
Database: 2005-05-02_03




SUBMIT A SAMPLE

Suspect a file or URL was wrongly detected? Submit a sample to our Labs for analysis

Submit Now

Give And Get Advice

Give advice. Get advice. Share the knowledge on our free discussion forum.

Learn More