HijackThis

HijackThis, sometimes abbreviated as HJT, is a free tool for Microsoft Windows for diagnosis and removal of malware infections. Originally created by Merijn Bellekom, it was later sold to Trend Micro. The program takes a heuristic approach to detect malicious software: Rather than rely on a database of known malware, it scans a computer to generate a list of differences to a known malware -free environment and allows the user to decide what from this list system should be removed.

Younger versions of HijackThis include additional tools such as a task manager, an editor for the hosts file and a scanner for Alternate Data Streams.

HijackThis is used primarily to diagnose malware infestation, as careless handling of his removal options considerable software can cause damage to a computer.

On January 18, 2012 Trend Micro has released the source code under the GPLv2 on SourceForge. Until then HijackThis was freeware.

Use

HijackThis generates a plain text log files with detailed entries on all findings. Most of these entries can be removed or turned off by HijackThis. Inexperienced users are advised to be careful with the last option, as HijackThis does not discriminate between wanted and unwanted entries. Thus, the user may inadvertently block important programs, so the operating system or peripheral devices can be made ​​inoperable. However HijackThis tried backup copies of files or registry entries that it removed to create that can be used to restore the system after a failure.

Often, the log files are placed in Internet forums, where experienced users to help you decide which entries must be removed. There are also tools that analyze the log files and try to clean up automatically, or the user to make proposals in this regard (see links). The use of these tools, however, is sometimes criticized as potentially dangerous for inexperienced users, as well as too unreliable and too inaccurate to replace an analysis by a human.