amir tohidlo

Safe Headers Scanner helps WordPress administrators identify common issues that may cause header-related problems. 
The plugin scans installed themes and plugins for: 
* Unnecessary whitespace before <code><?php</code> tags 
* Extra whitespace after closing <code>?></code> tags 
* Direct output (e.g., <code>echo</code>, <code>print</code>) before headers are sent
Results are displayed in a clear report, so you can review and fix potential issues easily.

Safe Headers Scanner

Scan themes and plugins for potential header issues such as whitespace before/after PHP tags or direct output before headers.

Kurt Payne

Scan uploaded files with ClamAV or run system commands against uploaded files.  This allows you to integrate third party malware scanners.
This plugin requires either ClamAV or another third-party scanner to be installed.  This plugin will pass uploaded files to the scanner and take appropriate actions based ont he results, but it is not, itself, a malware scanner.
If you have a dedicated server, you can install <a href="http://php-clamav.sourceforge.net" rel="nofollow ugc">php-clamav</a> for performance and convenience.
Banner image from <a href="http://www.flickr.com/photos/runlevel0/3647554681/in/photostream/" rel="nofollow ugc">Eric Martinenz</a>

Upload Scanner

It may not have been updated in 4 years, but it's such a simple plugin that there's really no reason to... and it still works great with your server's ClamAV install.

Still does exactly what it claims

Scan all uploaded files with ClamAV or your favorite malware scanner

Safe Headers Scanner vs Upload Scanner