Scammers use Symantec, DNS holes to push adware

IDG News Service - Online scam artists are manipulating the Internet's directory service and taking advantage of a hole in some Symantec Corp. products to trick Internet users into installing adware and other annoying programs on their computers, according to an Internet security monitoring organization.
Customers who use older versions of Symantec's Gateway Security Appliance and Enterprise Firewall are being hit by Domain Name System (DNS) "poisoning attacks." Such attacks cause Web browsers pointed at popular Web sites such as Google.com, eBay.com and Weather.com to go to malicious Web pages that install unwanted programs, according to Johannes Ullrich, chief technology officer at the SANS Institute's Internet Storm Center (ISC).
The attacks, which began on Thursday or Friday, may be one of the largest to use DNS poisoning, Ullrich said.
Symantec issued an emergency patch for the DNS poisoning hole on Friday. The company didn't immediately respond to requests for comment today.
The DNS is a global network of computers that translates requests for reader-friendly Web domains, such as www.computerworld.com, into the numeric IP addresses that machines on the Internet use to communicate.
In DNS poisoning attacks, malicious hackers take advantage of a feature that allows any DNS server that receives a request about the IP address of a Web domain to return information about the address of other Web domains.
For example, a DNS server could respond to a request for the address of www.yahoo.com with information on the address of www.google.com or www.amazon.com, even if information on those domains wasn't requested. The updated addresses are stored by the requesting DNS server in a temporary listing, or cache, of Internet domains and used to respond to future requests.
In poisoning attacks, malicious hackers use a DNS server they control to send out erroneous addresses to other DNS servers. Internet users who rely on a poisoned DNS server to manage their Web surfing requests might find that entering the URL of a well-known Web site directs them to an unexpected or malicious Web page, Ullrich said.
Some Symantec products, such as the Enterprise Security Gateway, include a proxy that can be used as a DNS server for users on the network that the product protects. That DNS proxy is vulnerable to the DNS poisoning attack, Symantec said on its Web site. Symantec's Enterprise Firewall Versions 7.04 and 8.0 for Microsoft Corp.'s Windows and Sun Microsystems Inc.'s Solaris have the DNS poisoning flaw, as do Versions 1.0 and 2.0 of the company's Gateway Security Appliance.
Internet users on some networks protected by the vulnerable Symantec products

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