“Who Sent This E-Mail?”

Stephan Gmelin

By: Stephan Gmelin, PCX Technologies 

Common Sense is a very effective tool protecting your computer networks

We all know that viruses and malware are the main threats we need to guard against. We know it so well that we occasionally forget that common sense is a very important layer in the layered defense strategy that has proven the most effective protection of computer networks. Recently I became clear again that an occasional reminder to the user community to utilize common sense as a defensive layer can pay very high dividends indeed.

About two years ago you may have heard about that the FBI was warning about the “Crypto” or “CryptoLocker” virus. The “CryptoLocker virus” is an example of ransomware, a class of malware that, once it has infected a particular computer system it seeks out shares on the system. It infects the shares and locks access to the files on the computer and the infected shares unless a ransom has been paid in return for a decryption key.

Well after 2 years and its first occurrences we have now reached CryptoLocker version 3.0. While previous versions of this nasty ransomware were distributed via e-mail with file attachments “Filename.exe” and were easily recognized as: “This is a file type I need to be careful with”. CryptoLocker 3.0 now gets embedded in pdf files.

One way the ransomware has spread recently is via e-mails offering to help with installation of the new Windows 10 operation system by just opening an attached pdf file. Once the attachment was opened the computer and all its shares, regardless of having antivirus software installed, were infected and locked and a ransom note requiring payment of $500 in BitCoin within a week became visible on the computer screen and all the infected shares.

Cleaning the computers and shares and reconstituting the computing environment from back-up is very time consuming and the productivity loss can be extremely costly. The criminals involved in the scheme are counting on this and hope to collect as many $500 payments as possible.

Everyone should be aware that the first line of defense against these types of attacks is as simple as paying attention to the senders e-mail address. If you do not recognize the e-mail address of the sender be doubly cautious as to what you do with the e-mail or the attachments. Taking 5 minutes and reminding your employees to look at who send an e-mail they are about to open can save you thousands of dollars.

No comments yet.

Leave a Reply