How Your Computer Can Be Infected – Volume 2: Worms

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We recently wrote to you about what a computer bug is, this time we’ll focus on the “worm” device. In cooperation with Avast., A Czech manufacturer of antivirals and other ways of securing your devices, we have prepared another part of the series on computer and online security.

Right from the beginning, we should probably clarify what is actually the difference between the worm and the virus and what links them. Both can be classified as malware – malicious software. They both spontaneously spread, and so they get into more and more computers, tablets, smartphones … While the virus puts its copy into another program through which it is spreading, the worm itself is a program. After the boot, the virus searches for other files to enroll, increasing the chances of a home being taken. The worm dispatches your copy yourself – it can be emailed or copied to a portable USB drive. It can exploit the vulnerabilities of the target system, expand and run itself remotely. In some cases, the worm does not directly spread its copies, but only links to download itself, using a chat application (skype, facebook chat …) or SMS messages. If a user downloads and starts a file from a link, it infects their devices.

Dissemination, though having a major influence on how successful a worm is, is not its only goal. He always has some bad luck. Like a virus, it can cause the device or its part to stop working or it will work badly, unusually. Sometimes it deletes files, sometimes encrypts them, and forces us to pay for us to reuse them. In terms of banking services, the most dangerous is the worm that scans the computer and collects personal and sensitive data about its users.

How to defend yourself? Follow the 4 rules

1) Do not download and open unknown or suspicious attachments . Among the suspects are various promotional offers, chain mail attachments (usually with the promise: Send this email to 10 friends and meet your true love within a week!), Announcement of a win in the contest without any participation, and so on. Avoid attachments that contain executable programs. These include not only EXE files, but also various documents that ask users for permissions, such as to run macros.

2) Do not click on suspicious links . The same rules apply to them as for attachments.

3) Install a reliable antivirus and update it regularly. Not only will the worm help you uncover and then eliminate, but thanks to it you can completely prevent the worms.

4) Use strong passwords . A strong password is not a word traceable in the dictionary, it has more than 8 characters, lower case, digits, and special characters. We recommend reading our article Are you well protected?

We advise you to keep our advice not only when using computers but also mobile phones.

“We are currently processing approximately eighteen thousand malware samples for mobile phones per day. Of which approximately three thousand are harmful to the device and can cause unwanted behavior or financial damage, “warns Filip Chytry, security analyst at Avast.

We also recommend that you read our article 10 on the safe use of smartphone .

In conclusion, we have five of the most famous computer worms for you to better understand where it can lead when we do not regularly roast our equipment:

Mydoom – The internet appeared in 2004, in several variants. He attacked the 32-bit edition of Microsoft Windows. It was emailed and reportedly the fastest worm that has infected the highest number of machines so far. Its goal was to allow an attacker to access the Internet from an infected device, bypass authentication and system authorization to obtain sensitive data or send spam. The losses are estimated at $ 39 billion.


Conficker
– The Internet began to crawl in 2008 and spread through Windows operating system errors, through shared network drives and launching portable devices such as flash drives, etc. The attacker could have infected the computer remotely, blocked system updates, including anti-virus programs, finished. Total damage is around 9 billion US dollars.

Sasser – began using bugs in Windows 2000, XP and 2003 in 2004. While most worms spread via e-mail or links, Sasser used the open ports of the computer. It caused restarting computers immediately after starting, but blocked and slowed down the data transfer, leading to stopping air traffic, disabling X-ray at Lund University Hospital, or cutting off the UK Coast Guard from Map Services. It is estimated that the losses it caused are $ 3.5 billion.

Code Red – appeared in the morning of July 19, 2001 and spread over the world over just 14 hours. It infected over 359,000 devices with the Microsoft IIS Web server. He stopped himself-his author had him programmed to stop spreading at midnight. Fortunately, infected devices may not end up in scrap, but with a slowdown in Internet connectivity, it has caused damage estimated at $ 2.6 billion.

SOBIG.F – during the month it was spread in 2003, it came to every fifteenth e-mail. He distributed all the addresses he found in his system – not just those in the directory, he searched for the content of text documents. He is estimated to have lost $ 2.5 billion during his short life.