In the third quarter, spam of all types represented an average of 82.3 percent of all email traffic and malicious spam surged to a record high of 4.6 percent of all email, according to a report from security software vendor Kaspersky Lab.

The more than doubling of spam emails containing malicious attachments from 1.9 percent last quarter to 4.6 percent this time around was mainly due to the closure of the SpamIt partner program in September that was and has been responsible for delivering "enormous volumes" of pharmaceutical spam this year, Kaspersky Lab researchers said in the report.

The report found that the SpamIt partner program websites, Spamit.biz and Spamit.com, did acknowledge shuttering their so-called partnership program with other would-be spammers for a number of reasons including the fact that MasterCard announced it would no longer execute payment transactions for medicine via the SpamIT partner program.

While that was good news for consumers and legitimate pharmaceutical sites, it was short-lived.

"Based on available data, the upswing in malicious mail traffic during late September appeared to be connected to the announcement of the shutdown of the prominent SpamIt partner program, which specialized in pharmaceutical spam," the report said. "Some of the spammers working with this program apparently switched to working with partner programs that send out mailings containing malicious code instead."

This proliferation of malicious spam, which includes attachments that are designed to trick people into sharing personal information, peaked at 6.3 percent of all email traffic in August.

Kaspersky Lab and other security software vendors are warning Internet users to be on the lookout for a variety of increasingly sophisticated malware traps that are or will use the upcoming holiday season and pop-culture events, such as the release of the new Harry Potter movie to lure people into clicking on the tainted links.

Similar scams using Facebook, eBay and Apple gift cards were among the most successful and damaging malware campaigns in the quarter.

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Despite the high-profile arrests of more than 100 people accused of operating an international phishing syndicate in September, hackers were still busy targeting people using popular sites, including PayPal, which was targeted in 56 percent of all coordinated phishing attacks. eBay checked in second at 8.4 percent and Facebook was next at 6.6 percent.

The U.S. was still the leading source country for spam in the third quarter, accounting for 12.9 percent of all spam emails. India checked in second at 7.6 percent, while Vietnam (5.1 percent), the UK (4.9 percent) and Russia (4.9 percent) rounded out the top five.

Kaspersky researchers said security software vendors and Internet users need to know that malware using spoofing technology that's designed to make the attachments look like HTML pages is on the rise. In the third quarter, the Trojan-Spy.HTML.Fraud.gen program was the most popular piece of spoofing malware uncovered by Kaspersky filters.

Once a user clicks on this type of malicious link, he or she is redirected to a bogus bank or e-payment site that asks for log-in credentials and other personal information. Those who fall for the ruse end up having their most sensitive data forwarded to cybercrooks that attempt to access and steal their funds.

"What differentiates this technology from traditional phishing techniques is that the address line in the browser does not show the true web address to which a user will be redirected, but a fake address that looks just like the official website’s address," the report said. "This technology can fool even the most cautious of users."

Larry Barrett is a senior editor at InternetNews.com, the news service of Internet.com, the network for technology professionals.

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