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Computer Crime / Digital Discovery / CCTV Image Recovery / Computer Forensics

Archive for May, 2014

SQL Injection Attacks

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A colleague of mine has received a notice from Google via his Web Master Tools account telling him that is site has been hacked:

“Unfortunately, it appears some pages on your site may infect visitors with software designed to access confidential information or harm their computers. You may not be able to easily see these problems if the hacker has configured your server to only show malicious content to certain visitors. To protect visitors to your site from malware, Google’s search results now display a warning when users click a link to your site.”

He’s yet to discover how this was accomplished but my money is on an SQL injection via the sites online database. SQL injections can be used to upload code to a web site, often a PHP file which can then be run remotely by the hacker and take control of the host web site. Taking control usually means redirecting the web traffic off to somewhere else (like a malware / trojan site).

Captcha exampleGoogle monitors web sites and attempts to detect when they have been compromised. This is how my colleague found out. SQL injection attacks are common way hackers use to take control of web sites but they are not the only way. Another common way is to gain access to the web site by cracking a username and password. Many sites these days have an extra page at login that introduces a Captcha into the login sequence – a code that is difficult for machines to read and easy for humans. You can read more about Captcha here: http://www.captcha.net/

Of course, this method is not 100% secure. While it’s often easy for people to identify the words or number sequence in the captcha boxes, it’s not an impossible task for a machine and there are many types of captcha software available that are able to crack many of the captcha codes. Also it’s possible to get captchas read and cracked by humans. Often in poorer countries – there are rooms of computers with people sat at them whose job is to type what they see. This is then relayed back to the captcha program and the captcha is broken and the system accessed.

Written by Betty

May 23rd, 2014 at 8:40 am