During our daily research and quest to locate harmful software we come across
many types of applications and application components. Our current database has
literally millions of file samples from users with potentially infected systems.
Part of any researchers duty, is to look at the various properties of a file
such as installed location, internal version information, linked libraries and
other items that can provide "clues" about what the software actually does and
if it represents a potential threat. Many times we have files that are not
in their native environment, meaning that we have a few samples of the file, but
not the entire system configuration they were originally installed. This can
make it difficult to properly differentiate between harmful and legitimate
software components.
Spyware/Malware applications often try to disguise themselves as legitimate
software components by using the same name as a windows component but place
themselves in a different folder. A classic, and often used, example of this are
the SVCHOST.EXE variants. The real SVCHOST.EXE which is used by Windows to host
services executes from the system folder of Windows, which is typically located
in C:\Windows\System32 for most users. We find variations of this file such as
SVOHOST.EXE, SVSHOST.EXE or files with Unicode characters that make them appear
as "SVCHOST.EXE" when viewed through explorer.
We are trying to encourage developers to start fully filling out their version
information with legitimate information such as product name, copyrights,
websites to download the software and possibly listing MD5, or other "hashes"
for verification of legitimate components. Naming components with recognizable
names is also good practice. This would make the researchers job easier and more
accurate and help prevent "false positives". A false positive is where a
legitimate file looks and acts like a potentially harmful piece of software and
ends up in a spyware or virus database to be blocked. Developers should also
avoid installing anything in the Windows folder unless absolutely required.
Items with random looking names, with no version information are immediate red
flags to any spyware or virus researcher!
With the number of harmful applications appearing at an alarming rate today,
developers should do everything they can to make sure their applications are not
flagged as harmful applications due to non-standard programming practices,
installation and naming conventions!
Posted : 11/02/2005 - 08:18:40 AM by Nick |