Tag Archives: botnets

Ransomware: Another Reason for Back-Ups

Among the many kinds of wicked online traps that users must beware, one of the most vicious kinds is called “ransomware“. This is a generic term for a type of malicious software that encrypts all or the most useful of the victim’s files, making it impossible to open or do anything until a ransom is paid to the cybercrooks. As in many kidnapping cases, their demands can greatly escalate if not paid quickly. But even if the ransom is paid, the victim very often does not get what was taken back. Fortunately, this last summer, a particular nasty specimen called CryptoLocker was finally broken open by two Internet security firms, FireEye in California, and Fox-IT in the Netherlands. Once they recovered the encryption keys, they put up a free site, decryptcryptolocker.com, to help victims get their precious files back. The details of how they were able to do this are sketchy, but the opportunity apparently arose after an international effort by law enforcement agencies, Operation Tovar, successfully took down the GameoverZeus botnet. Since then other tools and policies to avoid infection have been developed. CryptoLocker is usually spread by email attachments but can also be spread through by malicious websites exploiting outdated browser plug-ins. More information about how it works can be found here. Though the malware itself is surprisingly easy to remove, decrypting files is not so easy. Thus the tools. There is, however, an easier way of dealing … Continue reading

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US Leads the World in Spam

One interesting fact that didn’t make it into this month’s newsletter article on “The Secret Life of Spam” is that the United States leads the world in the overall volume of spam produced. And by a huge margin, too: according to security site Sophos, 24% of all spam generated this spring. That’s nearly a quarter! France and China, the runners-up, come in at less than 7% each. The full results can be accessed here. The results may be surprising because we tend to think of spam originating in Russia or Nigeria, or the actual place where the criminals who generate it live. But spam is a world-wide problem, and one would think the bad guys generally know enough to not spoil their own nests. Instead, the countries which actually generate the most spam are those where the most computers are infected with malware. The US merits the top billing for volume not so much due to poor security practices, but to our large and highly-connected population. When the overall amount is divided by population, the US doesn’t do so badly. In a per-person comparison, we come up merely twelfth, near the bottom with Bulgaria and Belarus being tops at 2.7 and 1.9 times the American rate. However, the US is still spewing a lot of crap messages, and if you’re infected, you’re part of the problem. Once your machine becomes part of a botnet, it’s essentially a zombie out of … Continue reading

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Web Security Snapshot Has Some Surprises

Symantec, a major Net security company, has published a report on Internet security threats of 2011. It’s an interesting snapshot of trends and statistics that makes sobering reading, along with a few eyebrow-raising surprises. Here are some of its highlights: A dangerous new trend among criminals is using shortened URLs to distribute and disguise spam and phishing attacks. These links are conveniently provided by numerous websites to handily replace lengthy strings in addresses, but where they actually point to may be hard to guess. Users are advised to use preview tools to check them out before clicking. Social media sites, especially Facebook, have been cleverly used to spread links to infected sites by crooks taking advantage of people’s expectations and profiles. People using social networking sites are cautioned to be careful about what personal information they post, and when clicking on URLs in email or posted on social media sites even when they come from friends or trusted sources. Macs are not immune: the first Mac-based botnet occurred in 2009. New threats emerged in 2011, including Mac Defender, a fake antivirus program that installs itself without permission. Symantec claims to have identified 4,989 new computer vulnerabilities in just 2011. However, the number of new problems with popular browsers has decreased slightly, Google Chrome having the most dramatic reduction. The amount of spam is actually decreasing, from over 88% of all email in 2010 down to 68% by the end of … Continue reading

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