Since you have access to the available information on Combofix, let me expand on what Blade Zephon said about HijackThis.
HijackThis is an advanced enumerator
(similar in some respects to a registry editor) that is used to display certain areas of the Windows registry where the majority of malware reside. HijackThis will scan these areas of your system and then create a log to help diagnose the presence of undetected malware in known hiding places. However, since HijackThis only scans certain areas of your system/registry, a hijackthis log may not always show all the malware on your system. Most of the log entries are required
to run a computer and removing essential ones can potentially cause serious damage
such as loss of Internet connectivity or problems with your operating system which could preventing it from starting. Using HijackThis requires advanced knowledge about the Windows Operating System and relies on trained experts to interpret the log entries
and investigate them in order to determine what needs to be fixed.
And just because you "fixed
" something with HijackThis, that does not mean you have a clean system. There are specific files and folders which must be deleted afterwards. HijackThis does NOT delete them. Futher, removing entries in HijackThis before the problem is properly identified can make the malware undetectable to other detection and removal tools
. Full system scanning tools like SUPERAntispywre, Malwarebytes' Anti-Malware, Spybot S&D and SpySweeper will remove the registry entries as well as the related files which results in a more complete removal process. HijackThis should only be used to clean up the entries left behind, after you have properly removed the malware.
Since HijackThis is a powerful tool that requires advanced knowledge about the Operating System and can cause system damage if incorrect instructions are given, only designated trained experts are allowed to help people with using HijackThis. If you do not have advanced knowledge about computers or training in the use of this tool, you should NOT fix anything using HijackThis
without consulting a expert as to what to fix.
With that said, there are tutorials available for advanced users which will help you understand more clearly about the use of HijackThis and what it does.