HijackThis

1. HijackThis - A general Homepage Hijacker Detector and Removal Tool By: Tahira Farid 60-564 Project 1 Fall 2004

2. Overview • Browser Hijacking and Why • The Techniques • Preventing a Hijack • HijackThis- A Hijack Removal Tool • Download Information • Getting around with the tool

3. Overview (cont.) • Testing • Summary • Important things learnt • Useful Links • References

4. What is Browser Hijacking? • Where browser’s default settings is forcibly modified by using scripting tools • Spyware takes over our internet settings, Redirects our searches and steals our homepage • adding links to favourites • changing homepage persistently - scripting - changing registry values - auto-running programs - secret files put on the hard disk

5. Why Hijacking? • Bring us back to a website or a sponsor’s site of Hijacker’s choice • Generate advertising revenues • Keep users trapped in their sites • Expand website’s traffic • Is it Reversible? -as easy as to switch the internet options back -as crucial as to undo the changes by going to windows registry

6. The Techniques • Multiple Windows pop-ups while leaving the site • Windows half off screen hard to close and allows no control • Offering “freebies” in their sites • Installing AOL software, messenger, ICQ adds http://free.aol.com to IE’s trusted sites zone without our permission-can download activeX, run scripts, perform various actions. • Removing internet options from tool menu and control panel • Changing reg settings to reset homepage • Installing program to reset homepage on reboot

7. Preventing Hijack • Various anti-hijacking and anti-virus tools available. • HijackThis- utility tool to remove browser hijacks, viruses, trojans & spyware • Does not target specific prog./URLs • Targets methods used by hijackers

8. HijackThis • Developed by Marijn • Freeware • 178 KB • latest version: 1.98.2 • Intended for advanced users • Increasingly updated to detect & remove new hijacks • Runs on all windows OS

9. Download Info & caution • http://www.spychecker.com/program/hijackthis.html • Required to place it in its own folder otherwise backups will not be made. • Recommended to be used after running spybot or spyware/hijacker remover- malware files will be left behind. • Requires knowledge in windows and OS in general. • If deleted entries without knowing- problems as IE not working, running windows.

10. Caution (cont) • Scans registry and various files in HD. • Entries similar to what a spyware/hijacker program would leave behind • Interpreting the results can be tricky. • Legitimate programs get installed in similar way hijackers get installed. • Extra causion should be taken fixing a problem.

11. Getting started • Go to the desired folder where hijackthis was created from zip unpack. Double click on hijackthis.exe

12. Scan results • Each line starts with a section name

13. Info on selected items • To know info about a selected obj

14. Fix entries • Select an item to fix/remove

15. Restoring items deleted mistakenly • We can make backup & restore items for erroneous scenarios for items which were removed but legitimate. • Under config button

16. Generating startup listing • Has a built-in tool to generate listing of all the prog that launch when comp starts. • Under config, Misc tools option.

17. Process Manager • Built-in tool to 1) Kill processes that are currently running 2) Check what DLLs are loaded in a particular process • Under config, Misc tools option

18. Process Manager (cont.)

19. Hosts File Manager • View our host file, • Delete lines • Toggle lines on/off • HijackThis will add a “#” sign before the line to comment it out so that it will not be used by Windows.

20. Delete on reboot • Sometimes files obstinately reject to get deleted from the system by any traditions means. • Could be virus/ spyware • HijackThis allows windows to delete the file on reboot.

21. HijackThis log • Each line on the scan list starts with a section name • Each entry has a 2-letter code to say what it is.

22. Testing • Windows XP SP2 • Running spybot S&D, ad-aware • Specific problem in IE: always redirects to http://213.159.117.134/index.php • Even using spybot S&D, AboutBuster, Spywareblaster, Ad-awareproblem was still there • Following entries were deleted after scan: • O2 - BHO: (no name) - {549B5CA7-4A86-11D7-A4DF-000874180BB3} - (no file) 02 entries refers to BHO- plugins for browser that extend the functionality of it. Used by spyware & legitimate programs. CLSID refers to reg. entries that contains info about BHO/toolbars. This particular entry means the entry exists in the registry but the associated file does not exist. Therefore cleaned to tidy up the registry.

23. Testing (cont.) • R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://213.159.117.134/index.php • R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://213.159.117.134/index.php • R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://213.159.117.134/index.php • R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://213.159.117.134/index.php • R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page = http://213.159.117.134/index.php • R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page = http://213.159.117.134/index.php R0,R1 entries refer to IE start page & search functions. The url R0, R1 are pointing to is unwanted. Therefore cleaned to get rid of it.

24. Testing (cont.) • O4 - HKLM\..\Run: [SysTime]  startup itemC:\WINDOWS\system32\systime.exe  Trojan downloaded • O4 - HKCU\..\Run: [SysTime] C:\WINDOWS\system32\systime.exe 04 entries refer to app that are listed in certain keys in reg/startup folders and are loaded automatically when windows starts. Here 04 entry shows a CoolWebSearch Trojan. Therefore fixed by HijackThis. The corresponding file C:\WINDOWS\system32\systime.exewas deleted by running windows on safe mode after fixing with HijackThis.

25. Testing (cont.) • O16 - DPF: {15AD4789-CDB4-47E1-A9DA-992EE8E6BAD6} - http://public.windupdates.com/get_file.php...edceabcca450006 016 entries refer to ActiveX obj-programs that are downloaded from websites and stored in our computer. Also referenced in the reg by their CLSID. Here the object/URL could not be recognized from where it was downloaded. Therefore cleaned by HijackThis. HijackThis also deletes the offending file from C:\Windows\Downloaded Program Files- where the these types of objects are stored.

26. Testing (cont.) • Booting with safe mode following file was deleted • C:\WINDOWS\system32\systime.exe • Temp internet files were deleted • System rebooted normally, Ad-aware was run to do some more cleanup. • No bad entries were found in the new log.

27. Summary • HijackThis is a very powerful tool to root out serious infestation or attack in our system. • we should be cautious enough, since incorrectly removing inappropriate objects can cause problems with legitimate programs and compromise our system. • Many online forums & tutorials for inspecting logfiles. • Useful links available for CLSID, startup lists. • we need a great deal of devotion, commitment and knowledge towards our system security. • HijackThis by itself can not make our system secure from Hijackers, we need other relevant tools as well to detect and remove spyware and viruses.

28. Important things learnt In order to keep computer clean and secure: • Make our Internet Explorer more secure by customizing security options. • Use an AntiVirus Software • Use Spyware & Malware remover utility tools Spybot S&D, Ad-aware, CWShredder , HijackThis, SpywareBluster • Update our AntiVirus Software • Use a Firewall • Visit Microsoft's Windows Update Site Frequently • Update all these programs regularly

29. Useful links • HijackThis log file analysis: http://www.hijackthis.de/index.php?langselect=english • TonyK's Browser Helper Obj (BHO) & Toolbar list: http://www.sysinfo.org/bholist.php • PacMan's Start-up list to find the entry and see if it's good or bad. http://www.sysinfo.org/bholist.php

30. References • http://www.spywareinfo.com/%7Emerijn/htlogtutorial.html • http://www.bleepingcomputer.com/forums/index.php?showtut orial=42#RDiag

31. Thank You!