Blaster (computer worm)
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The Blaster worm (also known as Lovsan or Lovesan) was a computer worm that spread on computers running the Microsoft operating systems, Windows XP and Windows 2000, during August 2003.
The worm was first noticed and started spreading in the wild on August 11, 2003. The rate that it spread increased until the number of infections peaked on August 13. Filtering by ISPs and widespread publicity about the worm curbed the spread of Blaster.
The worm was programmed to start a SYN flood on August 15 against port 80 of windowsupdate.com, thereby creating a distributed denial of service attack (DDoS) against the site. The damage to Microsoft was minimal as the site targeted was windowsupdate.com instead of windowsupdate.microsoft.com to which it was redirected. Microsoft temporarily shut down the targeted site to minimize potential effects from the worm.
The worm spread by exploiting a buffer overflow in the DCOM RPC service on the affected operating systems, for which a patch had been released one month earlier in MS03-026 and later in MS03-039.
The worm contains two messages hidden in strings. The first:
I just want to say LOVE YOU SAN!!
is why the worm is sometimes called the Lovesan worm. The second:
billy gates why do you make this possible ? Stop making money and fix your software!!
is a message to Bill Gates, the co-founder of Microsoft, and the target of the worm.
On August 29, 2003, Jeffrey Lee Parson, an 18-year-old from Hopkins, Minnesota was arrested for creating the B variant of the Blaster worm; he admitted responsibility and was sentenced to an 18-month prison term in January 2005.
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[edit] Side effects
Although the worm can only spread on systems running Windows 2000 and Windows XP (32 bit), it can cause instability in the RPC service on systems running Windows NT, Windows XP (64 bit), and Windows Server 2003. If the worm detects a connection to the Internet (regardless of dial-up or broadband), this can even lead to the system becoming so unstable that it displays the following message and then restarts (usually after 60 seconds):
Windows must now restart because the Remote Procedure Call (RPC) Service terminated unexpectedly.
[edit] Mitigation
This error message and the Windows restart can be avoided by changing the properties of the Shutdown service, buying an infected user enough time to remove the virus from their system and install a patch removing the vulnerability. The procedure is done as follows:
- Go to Start->Run
- Type "services.msc" and press Enter
- Find the "Remote Procedure Call" service (not RPC Locator), right-click, and select Properties
- Select the Recovery tab, and set all failure actions to "Take no Action"
- Select OK
Because the Remote Procedure Call is an integral part of Windows, the failure actions should be reset to "Restart the Computer" as soon as the Blaster worm is removed.
Another method to stop the computer from restarting is as follows:
- Go to Start->Run
- Type "shutdown -a" and press Enter
If run as an Administrator, this will stop the reboot (-a stands for "Abort").
The above procedure must be done within the time limit displayed in the shutdown notice. The "shutdown.exe" file is not available within Windows 2000 unless you extract it from the Windows 2000 resource kit.
Additionally, systems running the Open Software Foundation's Distributed computing environment can be affected by traffic generated from the worm. Packets generated by the worm can cause DCE to crash causing a Denial of Service of DCE.
A rule-of-thumb for users of Microsoft Windows is that they should remain vigilant in keeping up-to-date with updates from Microsoft, as well as anti-virus software. Windows Update is especially crucial because malware such as the Blaster are often created upon vulnerabilities that are addressed by recent software patches, in hopes that many users are not yet fully protected.
[edit] Trivia
After close examination of Blaster's code, researchers found Parson's name embedded in the code which police later used to convict him.[citation needed]
