Really strange error on my store! Please Help!

When my store loads up I get this error flashing on the screen before the page loads (the error remains, just hidden a bit by my background image. Any thoughts? One of my computers cannot view the admin page because of the same error (another computer that was logged in as admin is still useable).

Website was working fine a few hours ago, I didn't change anything.

#4f57d2# if(empty($f)) { $f = ""; echo $f; } #/4f57d2# #4f57d2# if(empty($f)) { $f = ""; echo $f; } #/4f57d2# #4f57d2# if(empty($f)) { $f = ""; echo $f; } #/4f57d2#

Any thoughts.

Thanks,
T556

your store might have been compromised. http://forum.opencart.com/viewtopic.php?f=20&t=98644

Hacked. The "#4f57d2#" would be a color code without the trailing "#". The echoes in this instance don't seem to be doing much. Does not spring from anything server did. Third instance of same in days.
Example, http://forum.opencart.com/viewtopic.php ... 34#p431733
also links to the 4 pages of http://forum.opencart.com/viewtopic.php?f=20&t=98644 through http://forum.opencart.com/viewtopic.php ... 60#p431729
More, http://forum.opencart.com/viewtopic.php ... 31#p427229

What is the URL? See PM.

This has crippled hundreds of sites today please contact your host.

From what I am seeing, if you have the problem with six digits (numbers, letters, like a color code) between a pair of #, then put it into Maintenance Mode right away, some of these (apparently not all, but enough for concern) are or are intimately associated with live infections.

What at the moment is second above seems to me to be spam, source is not OC.

Glad to have stumbled upon this article, implemented the changes on the article that were suggested.