Virus Scanners many not protect you – the best defense is common sense.
Has your company been infected by CryptoWall as yet? CryptoWall is a virus that is delivered primarily by email. Its sole purpose is to infect your system and encrypt documents, pictures and videos so that you cannot access them. CryptoWall can detect network drives whether they are connected by a drive letter or a UNC. When it has finished its encryption work, CryptoWall presents a ransom note asking for a Bitcoin deposit in order to provide the decryption password.
Unfortunately, the decryption technology is broken. If you pay the fine you will not receive the decryption key, you will just be left with a bunch of files that you can no longer use.
How do people get infected? Through social engineering. Here are some examples:
Logmein Account Requests
If you have Logmein or some other account, you might be tempted to click the link in this email:
In this case the language of the above message is very good. You might not think to consider if the links are valid. But if you were to hover over the links you would see that neither of them point to Logmein. On link points to an infectious ZIP file.
Again, the link does not point to the Royal Bank and the request is bogus.
These types of social engineering emails attempt to fool you into clicking the link. Do not click links in emails unless you are sure of the source and are expecting the mail. A good way to check is to forward the mail back to the person that send it on ask them to confirm that they sent the message to you.
We have said it before; a good recovery system is your only salvation for these types of viruses. Be wary and have a great backup system. Find out more information on how to spot social engineering scams at this link: https://www.us-cert.gov/ncas/tips/ST04-014.