Israel came in third place in the quarterly Spampionship League rankings, which rates countries according to per capita forwarding of spam e-mails. Israel’s placement went up four spots from last time. Sophos, a cyber-security company, published the list on April 17.

The CAN-SPAM Act of 2003 defined “spam” as the sending of anonymous and unsolicited bulk messages. Those e-mails may contain ads, malware, links to phishing sites and other unwanted phenomena, and often lack an opt-out mechanism or a legitimate return address. Clicking on the opt-out link that does appear in some spam messages will only guarantee you get even more spam, Sophos says

About 50 billion pieces of spam are sent each day, according to Yahoo Mail. Much of it is intercepted before reaching a recipient’s inbox, “arrested” either on the user’s Internet service provider servers or dumped into a spam folder when it gets to the inbox. Enough gets through to make spam extremely annoying. Many of those messages are likely to contain links to install malware or viruses on a user’s computer. Just the presence of these messages in a user’s inbox significantly raises the danger that they will be clicked, Sophos added.

Even if spam was nothing more than a nuisance, it would be costly, Sophos said. Companies spend more than $20 billion a year on spam interdiction, besides the costs associated with a slower Internet, the result of the excess traffic. According to Incapsula, a cyber-security firm, over 60 percent of Internet traffic is sourced from bots, programs that automatically forward the junk messages spammers rely on.

Spammers all over the world offload their malicious messages onto networks of computers and servers, which may be located in their home countries, for final delivery. “Cybercrooks don’t send their own spam: that would be expensive, and easy to track, and would point the finger of law enforcement right back at them,” said Paul Ducklin, an expert from Sophos. “Instead, the crooks co-opt innocent third parties — like you and me, or our friends and family — to send spam for them.”

Cyber-crooks, he said, “use malware-infected computers as remote control ‘spam robots,’ better known as bots or zombies, to churn out unwanted and illegal e-mails on their behalf. You end up paying for the bandwidth, carrying the risk and contributing to your country’s standing in the Spampionship.” A high ranking indicates that individual computers and servers are not protected, Sophos said. Spammers “adopt” computers into their spam bot networks when users inadvertently install malware on their computers by clicking suspicious links, which users, ironically, get in spam messages.

That appears to be what happened in Israel, Sophos said. The country’s presence on the list of most spam sent per capita population does not mean that the country has been invaded by an army of spammers, but it does mean that there are a large number of infected computers in Israel that are being used by spammers elsewhere. Too few people use effective malware and virus detection systems, and spammers are having a field day with under-protected Israeli computers.

Computers in the United States send out the largest number of spam messages, by far; over 16% of all spam is relayed through computers and servers in the US, more than three times second-place Spain. In terms of sheer numbers, Israel contributes just 0.9% of the world’s total of spam, said Sophos.

That’s because Israel is a small country, with fewer computers than the top spam-sending countries: the US, Russia, Italy, China, and Germany. For smaller countries, such as Israel, the benchmark of poor anti-spam security is the number of messages sent out relative to the population. On that benchmark, Israel does poorly, bested only by Belarus and Uruguay. Israeli computers on average relay more than three times spam than computers in the US, according to Sophos.

That Israel, a “Middle Eastern technology powerhouse,” figures so prominently in the Spampionship League is “the biggest surprise” of the Sophos findings, said Ducklin. Israeli computers have been on an unmistakable downward spiral of late — placing 12th in the per capita spam table in the third quarter of 2013, seventh in Q4 2013 and third in the latest ranking. “With a comparatively small population, Israel’s by volume contribution isn’t enormous (29th place with 0.9% of the world’s spam), but that per capita result — more than three times the rate of our benchmark, the USA — just isn’t good enough,” said Ducklin.

“Interestingly, Israel has a reputation for successfully incubating IT start-ups in the past 20-25 years, including numerous computer security related companies,” he added. “Perhaps that historical fact will be an incentive to computer users in Israel to scan their computers for malware? It certainly looks as though they’d help themselves and everyone else by doing so.”