Junk mail is no longer simply pleas for funds to help get an African prince and lawyer out of bother, or congratulatory notes to let you know you've won the Spanish lottery, but now often contain malicious codes or links designed to steal your data and raid your accounts.
The sophisticated ones often mimic a bank or popular online service in order to try and fool you into thinking the "security notice" or "account breach" requires you to resubmit your account details -- but where do such emails come from?
As the BBC reports, a team of Dutch researchers have endeavoured to find out, and say that roughly 50 percent of such unwelcome communications originate from only 20 internet service providers (ISPs).
Based on a survey of over 42,000 ISPs, the team found that such "bad neighborhoods," places where malicious activity was most likely, generally specialized in particular scams. For example, cybercriminals using U.S. ISPs like to send out phishing emails, whereas spam is likely to come from Asian variants.
Most malicious networks were based in India, Vietnam and Brazil. However, the finger was pointed at Nigerian ISP Spectranet as the most malicious network, with 62 percent of addresses under the ISP's control sending out spam frequently.
Although its often the case that hackers disguise their true location, the research may help security firms improve tools that detect whether the latest message in your inbox is legitimate or likely to be a scam.
"If security engineers want to reduce the incidence of attacks on the internet, they should start by tackling networks where attacks are more frequently originated," the researchers say.
Image credit: Sebastian Anthony