Symantec has discovered a bizarre ransom Trojan that eschews the usual
demand for payment in favor of asking its victims to fill in an online
survey to get an unlock code.
Given the name Shadowlock by the security firm
, the underlying engineering of the Trojan is much the same as any one of the numerous other examples of ransomware.
Infected Windows PCs display a dialogue box asking for the unlock code
and the hint that they can find it after visiting a website linking to a
list of different prize surveys or by downloading unnecessary software
such as a media player.
The box won’t clear until the survey code has been entered, and can’t be
closed using the task manager; attempts to delve into matters using the
command prompt, PowerShell, Regedit, or MSConfig are also denied as is
the ability to bypass it by invoking a restore point.
Entering the code incorrectly three times, or just attempting to close
the dialogue, causes the system to shut down. Upon a reboot the same
dialogue reappears after 20 seconds, the length of time the users have
to try and shut it down using the Task Manager.
Shadowlock can also nix browsers and certain system tools as well as consume free resources and disable the Windows firewall.
Other odd traits
Symantec was able to decompile the Trojan, which was built using .NET,
well enough to discover some of its more eccentric secrets. For example,
it also includes an Easter egg, a hidden routine that plays a the five-note theme from the 1976 alien abduction film Close Encounters of the Third Kind.
Other capabilities include being able to reverse mouse buttons and open the CD tray or open Windows utilities.
“It turns out the malware author has a sense of humor,” wrote Symantec researcher, Fred Gutierrez in his blog on Shadowlock.
He speculates that the survey tactic might be an experiment to see much
response it gets, or perhaps part of a genuine money-making scheme.
“These functions (as well as others) may find themselves being used in a future variant.”