Parent class: VirWare
Viruses and worms are malicious programs that self-replicate on computers or via computer networks without the user being aware; each subsequent copy of such malicious programs is also able to self-replicate. Malicious programs which spread via networks or infect remote machines when commanded to do so by the “owner” (e.g. Backdoors) or programs that create multiple copies that are unable to self-replicate are not part of the Viruses and Worms subclass. The main characteristic used to determine whether or not a program is classified as a separate behaviour within the Viruses and Worms subclass is how the program propagates (i.e. how the malicious program spreads copies of itself via local or network resources.) Most known worms are spread as files sent as email attachments, via a link to a web or FTP resource, via a link sent in an ICQ or IRC message, via P2P file sharing networks etc. Some worms spread as network packets; these directly penetrate the computer memory, and the worm code is then activated. Worms use the following techniques to penetrate remote computers and launch copies of themselves: social engineering (for example, an email message suggesting the user opens an attached file), exploiting network configuration errors (such as copying to a fully accessible disk), and exploiting loopholes in operating system and application security. Viruses can be divided in accordance with the method used to infect a computer:- file viruses
- boot sector viruses
- macro viruses
- script viruses
Class: Email-Worm
Email-Worms spread via email. The worm sends a copy of itself as an attachment to an email message or a link to its file on a network resource (e.g. a URL to an infected file on a compromised website or a hacker-owned website). In the first case, the worm code activates when the infected attachment is opened (launched). In the second case, the code is activated when the link to the infected file is opened. In both case, the result is the same: the worm code is activated. Email-Worms use a range of methods to send infected emails. The most common are: using a direct connection to a SMTP server using the email directory built into the worm’s code using MS Outlook services using Windows MAPI functions. Email-Worms use a number of different sources to find email addresses to which infected emails will be sent: the address book in MS Outlook a WAB address database .txt files stored on the hard drive: the worm can identify which strings in text files are email addresses emails in the inbox (some Email-Worms even “reply” to emails found in the inbox) Many Email-Worms use more than one of the sources listed above. There are also other sources of email addresses, such as address books associated with web-based email services.Read more
Platform: VBS
Visual Basic Scripting Edition (VBScript) is a scripting language interpreted by Windows Script Host. VBScript is widely used to create scripts on Microsoft Windows operating systems.Description
Technical Details
This is the Internet worm that was found in the wild in the middle of June 2000. The worm spreads via e-mail by sending infected messages from affected computers. While spreading, the worm uses MS Outlook and sends itself to addresses that are randomly selected from MS Outlook Address Book.
The worm is written in the scripting language "Visual Basic Script" (VBS). It works only on computers on which the Windows Scripting Host (WSH) is installed. In Windows 98 and Windows 2000, WHS is installed by default. To spread itself, the worm accesses MS Outlook and uses its functions and address lists. That is available in Outlook 98/2000 only, so the worm is able to spread only in case one of these MS Oulook versions is installed.
When run, the worm sends its copies via e-mail, installs itself into the system and copies itself to network drives. The worm also has the ability to spread through mIRC channels.
The worm contains a "copyright" string:
'MIRC/NETWORK/OUTLOOK/PIRCH.ShellScrapWorm by SimpleSimon / Zulu
Spreading
The worm arrives to a computer as an e-mail message with an attached SHS file that is a scrap package with a worm inside. The message subject may be different, and it is combined from three sets of strings:
"Fw: ", ""
"Life stages", "Funny", "Jokes"
" text", ""
Examples:
Fw: Jokes
Life stages
Funny text
The message body may be empty or one of these is present:
> The male and female stages of life.
> The male and female stages of life. Bye.
The message has the attached file "LIFE_STAGES.TXT.SHS" that contain worm inside.
Depending on system settings, the real extension of the attached file (".SHS") may not be shown. In this case, the filename of the attached file is displayed as "LIFE_STAGES.TXT".
Being activated by a user (by double-clicking on the attached file), the scrap package (SHS-file) activates its content. As soon as the attached file contains the VBS file inside, containing a Visual Basic Script program, this file is executed and the worm's script gains control.
The worm creates a text file in the temporary directory and displays it using the text editor. The file content is:
- The male stages of life:
Age. Seduction lines.
17 My parents are away for the weekend.
25 My girlfriend is away for the weekend.
35 My fiancee is away for the weekend.
48 My wife is away for the weekend.
66 My second wife is dead.
Age. Favorite sport.
17 Sex.
25 Sex.
35 Sex.
48 Sex.
66 Napping.
Age. Definiton of a successful date.
17 Tongue.
25 Breakfast.
35 She didn't set back my therapy.
48 I didn't have to meet her kids.
66 Got home alive.
- The female stages of life:
Age. Favourite fantasy.
17 Tall, dark and hansome.
25 Tall, dark and hansome with money.
35 Tall, dark and hansome with money and a brain.
48 A man with hair.
66 A man.
Age. Ideal date.
17 He offers to pay.
25 He pays.
35 He cooks breakfast next morning.
48 He cooks breakfast next morning for the kids.
66 He can chew his breakfast.
After that, the worm opens MS Outlook, gains access to the Address Book, obtains a hundred random addresses from each address list and sends messages with its attached copy to all of them. The message subject, body and attached file name are the same as the abovementioned.
The worm also installs itself into the system. It creates its copies in Windows directories with the names:
in Windows directory: LIFE_STAGES.TXT.SHS
in Windows system directory: MSINFO16.TLB
in Recicle bin: MSRCYCLD.DAT
Then the worm creates its copies with random names in root directories of all local hard drives and also in the "Programs" and "My Documents" folders. If a Windows startup folder exists on the network drive, the worm copies itself there.
The worm also drops files:
in the Windows system directory: SCANREG.VBS
- this file worm registers in the system registry in the auto-run section to be executed upon each Windows startup:
HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRunServicesScanReg = "WSCRIPT.EXE SCANREG.VBS"
- the worm creates a copy of this file in the Recycle bin:
RCYCLDBN.DAT
in the Windows directory: DBINDEX.VBS
- this file worm registers in the system registry in the ICQ section to be executed upon each ICQ startup:
HKEY_USERS.DEFAULTSoftwareMirabilisICQAgentAppsICQEnable = "Yes"
HKEY_USERS.DEFAULTSoftwareMirabilisICQAgentAppsICQParameters = "C:RECYCLEDDBINDEX.VBS"
HKEY_USERS.DEFAULTSoftwareMirabilisICQAgentAppsICQPath = "WSCRIPT.EXE"
HKEY_USERS.DEFAULTSoftwareMirabilisICQAgentAppsICQStartup = "C:WINDOWS"- the worm creates copy of this file in Windows system directory:
VBASET.OLB
As a result, the worm is re-activated each time Windows boots up or ICQ starts.
Spreading to IRC channels
The worm scans local drives and looks for an MIRC.INI file. In case this file is found in a subdirectory, the worm drops a SOUND32B.DLL file there. This file contains mIRC instructions that send a worm copy (LIFE_STAGES.TXT.SHS file) to all users that join the infected IRC channel. In MIRC.INI, the file worm adds the reference to SOUND32B.DLL into the "rfiles" section.
Other
The worm moves the REGEDIT.EXE program into the Recycle bin with the name RECYCLED.VXD.
Read more
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