Spam is big business. With the proliferation of botnets for hire, it takes very little effort for a spammer to send out thousands of messages at a time. These messages may contain links to websites peddling counterfeit products, or they may be laced with viruses, trojans, and various other forms of malware. The barriers to entry and costs incurred by spammers are very low
There seems to be no end to the global threat of malware spreading via spam and phishing emails and propagated by botnets around the world. Over the past few months, two threats have emerged. One is a banking trojan targeting users in Brazil, and the other is the now-infamous Cryptowall ransomware.
The banking trojans are spread via phishing emails containing CPL files, which are a type of library file that executes code once it is clicked on. Social engineering tactics are used to try to convince the message recipients that the attachment contains valuable information, such as an invoice or banking information.
The other big player in the malware arena is ransomware. A recent study has shown the proliferation of phishing emails with SVG files attached. These files, when downloaded and executed, open websites with what appears to be the CryptoWall ransomware.
The common theme for both of these threats is that the user was not exercising the proper amount of caution before opening email attachments. Both of these threats where spread via phishing emails, which use social engineering tactics to trick end users into opening these messages and clicking on links or downloading attachments.
Spammers know that end users are often the weakest link in fighting spam, so it’s in the best interest of companies of all sizes to educate their users on email safety. While most mail servers and spam gateways, such as MDaemon and SecurityGateway, have numerous tools for blocking spam & malware, no anti-spam solution is 100% fool-proof. Spammers are always seeking out new methods to trick users into opening their messages, so users must learn how to stay safe and recognize potential threats.
For a review of best practices for end users, review my post “Email Safety Tips for End Users.”