A dangerous worm from Germany is loose on the Internet.
Yarner (w32.yarner.a@mm) appears to be a newsletter about Trojan horses from a legitimate security site, but is actually a dangerous worm. Yarner is a Windows PE EXE file about 434K in size, written in Delphi. It uses its own e-mail engine to send copies of itself to others. Once executed, the worm deletes the Windows directory on infected computers.
At present, the infections are limited to Germany, however, a new variation could be produced in English or any other language. Because of the dangerous potential of this worm, Yarner ranks a 7 on the ZDNet Virus Meter.
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If executed, Yarner will copy itself to the Windows directory as notedpad.exe, overwriting the system's original Notepad application (notepad.exe). Whenever you launch Notepad, Yarner uses notedpad.exe to hide its presence. The worm adds two additional files: kerneI32.daa (which the worm uses to write e-mails) and kerneI32.das (which the worm uses to write known SMTP).
The worm then changes this registry file:
HKCU\Software\Microsoft\Windows\CurrentVersion\Runonce[random characters] = [random characters].exe There can be up to 100 random characters assigned to these values. To send e-mail, Yarner gains access to the Microsoft Outlook address book then scans all .php, .htm, .shtm, .cgi, .pl files in all subdirectories, looking for additional e-mail addresses. Yarner then uses its own SMTP engine (e-mail program) to send e-mails and connects to its own list of servers, including: 22.214.171.124 joy-go.gr.jp ctripserver.ctrip.com.cn 126.96.36.199 cocess.cocess.co.kr mail.bizpoint.com.sg ns2.webshock.co.kr olympus.mda.com.tr linux2.ele-china.com mailsvr.hanace.co.kr After it has sent copies of itself, Yarner then deletes all files in the Windows directory.