“You have received a secure message” well actually you have not, all you have received is a malware. Recently its seen that there are many emails spreading which contains malware and unlike other malware spreading emails which says about you winning lottery or you gaining a big sum of wealth ,etc. This malware laced email says that someone has sent you one secured and encrypted message and you need to download some file to read it, well and there you have it the malware infecting your computer as soon as you install it.
The email says the following (Please note I have removed the links and phone number for obvious reason)
You have received a secure message
Read your secure message by opening the attachment, SECUREDOC. You will be prompted to open (view) the file or save (download) it to your computer. For best results, save the file first, then open it.
If you have concerns about the validity of this message, please contact the sender directly. For questions about Key's e-mail encryption service, please contact technical support at <a phone number>.
First time users - will need to register after opening the attachment.
Help - < url link >
About IronPort Encryption - < url link >
The file which the email will offer you to download named securedoc.zip contains a Trojan horse , namely Troj/Zbot-DPM. The trojan is a part of notorious ZBot family of malware (also known as Zeus) can hijack your computer, making it part of a criminal botnet. Over the past few years these kind of ZBot trojans have been used to steal personal information,like email id password ,social networking sites id and password and even sed to stel money from bank. So you understand how much har can it cause if it infects your computer.