We want to alert you to a very urgent threat to the data on your computer systems called Cryptowall 2.0.
You should immediately advise your staff to not open ANY ZIP or PDF files that are sent to you through e-mail. This new virus arrives as an e-mail that contains a zip or PDF file that pretends to be an invoice, purchase order, bill, complaint or other business communication. If you receive such a message, you should verify with the sender that they did in fact send this message prior to opening the attachment.
This threat is specifically designed to defeat firewalls, anti-virus and anti-malware software. There is presently no known way to block these threats. If you open such an attachment, you won’t even know you have been infected until you attempt to access data on your network. Once infected, your data is inaccessible and current recovery steps are time consuming and expensive. We can not stress the severity of this threat enough.
The industry as a whole is actively monitoring this situation and working to implement updates as soon as they are available. In the meantime, I recommend you adopt a very conservative posture toward this threat by not opening any e-mail attachments you have not personally verified. We expect this threat to be active for the foreseeable future.
I know this causes a significant issue, and will be nearly impossible to implement. My suggestion is to pay attention to the content of the email. If the email is from someone who normally sends you PDFs, pay attention to the text of the email. Pay particular attention to make sure it “sounds like” the person. In other words, if they normally send a bill or PO and they send pretty much the same text, it’s probably legit. If there are things that are “not normal” for them, verify. Also, keep in mind the email signatures can’t be used to distinguish this. If it can be sent through Outlook, or whatever email client they use, that client will add the signature. I’m not sure if the emails are going through local accounts, or are just falsifying the email from address. PDF vulnerabilities affect all platforms, including Windows and Mac. I’m not sure what impact this has right now on Android and iOS products.