Spammers Expressing Faith on Unknown File Formats

According to security firm Symantec, spammers are nowadays using unfamiliar file formats so that their malicious attachments could successfully evade security filters, as per the news published by thestandard.com on August 19, 2009.

Some of these file formats include eFax that is the electronic fax format and the Internet Explorer web archive format, Multipurpose Internet Mail (MHT).

The security firm explained that eFax service allows a user to send and receive documents in a digital format, like an e-mail attachment. 419 e-mail scammers have commenced using EFX file format, noted the firm, for which it held wide usage of the file format and its simplicity responsible. However, experts have called it a mere experiment as an EFX file format sent in a spam e-mail cannot be opened.

Experts at Symantec also discussed the MHT file format attached with phishing e-mails. A webpage when saved as a "web archive" gets saved to a Multipurpose Internet Mail Extension HTML format with MHT extension. MHT file works in a similar way as an HTML file. It opens a legit-looking webpage like bank page and thereby, asks recipients for confidential financial information. So, the security of people receiving such e-mails is at big risk.

Experts at Symantec noted that experiments involving file attachment formats is not a new concept used by spammers, but generally themed on types popular among users such as DOC, HTML, TXT, etc.

Using new file formats for various spam campaigns is a method of tying to trick anti-spam filters as well as users. The use of less familiar file formats like EFX and MHT depicts that the spammers are not leaving a single stone unturned to spam unaware users. It is learnt that ZIP files and PDFs evolved as favorite assault tools in 2006. However, these are now difficult to go past anti-spam filters as the threat has now been recognized.

All-in-all, it's the user who should be careful while opening any e-mail attachment. Moreover, in order to be safe from falling victim of spamming or phishing attacks, it should be ensured that the e-mail sender is a reliable person or organization.

Related article: Spammers Continue their Campaigns Successfully

» SPAMfighter News - 9/2/2009