Email-Worm:W32/Sober.L
Summary
Sober.L worm was seeded in emails on 7th of March 2005. It has less functionality than the previous variant, composing a smaller amount of different messages. Sober.L sends itself as an attachment in email messages with English or German texts.
Removal
Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.
A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:
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Check for the latest database updates
First check if your F-Secure security program is using the latest updates, then try scanning the file again.
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Submit a sample
After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.
Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.
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Exclude a file from further scanning
If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.
Note: You need administrative rights to change the settings.
Technical Details
The worm is written in Visual Basic. The worm's file is a modified UPX packed PE executable about 45 kilobytes long. The unpacked worm's file size is around 142 kilobytes. The worm adds random garbage to the end of its file every time it installs itself on a computer.
Installation to system
When the worm's file is started it opens Write text editor with the following text as a decoy:
When the worm's file is run, it copies itself as "smss.exe" into the %WinDir%\msagent\system\ folder, created by the worm.
Sober.L worm adds startup keys for "smss.exe" in System Registry:
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run] " Services.dll" = "%WinDir%\msagent\system\smss.exe"
Also the worm drops the text file 'read.me' file to Windows folder.
Spreading in emails
The worm sends different types of email messages with English and 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 email 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
The worm ignores email addresses that contain any of the following substrings:
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
The worm composes emails with both English and German texts. If the worm sends infected messages to domains with suffixes '.de', '.ch', '.at', '.li' and also to 'gmx.' domain, it composes messages in German, otherwise English messages are composed.
The worm composes the following messages:
Subjects:
Your Password & Account number Ich habe Ihre email bekommen!
Body texts:
i've got an admin mail with a Password and Account info! but the mail recipient are you! it's probably an esmtp error, i think. i've copied the full mail text in the Windows text-editor & zipped. ok, cya...
---- or ----
Hallo, jemand schickt ihre privaten Mails auf meinem Account. Ich schaetze mal, das es ein Fehler vom Provider ist. Insgesamt waren es jetzt schon 6 Mails! Ich habe alle Mail-Texte im Texteditor kopiert und gezippt. Wenn es doch kein Fehler vom Provider ist, sorge dafuer das diese Dinger nicht mehr auf meinem Account landen, es Nervt naemlich. Gruss
Attachments:
MailTexte.zip acc_text.zip