Avast finds but cannot deal with Win32:BHO-KD (Trojan)

system · 2008-01-01T20:38:19.000Z

[b]Thanks Tech, it’s just that I already had Archive Scanning on and still it’s Access Denied. Temp files have all been checked and cleaned. All other programs I’ve installed recognise the Trojan but can’t do anything about it…even in Safe Mode/DOS mode.

I appreciate the links tho’ and have noted them to better bulk up my PC security.

But the problem still remains. I somehow need to force my ownership on the .dll file so I am authorised to delete it/move it to chest.[/b]

Tech post:2:

Can you follow the general cleaning process?

Disable System Restore and reenable it after step 3.

Clean your temporary files.

Schedule a boot time scanning with avast with archive scanning turned on. These can avoid the access denied problem (files in use). Send files to Chest and do not delete them directly.

Use AVG Antispyware; SUPERantispyware and/or Spyware Terminator to scan for spywares and trojans. If any infection is detected, better and safer is send the file to Quarantine than to simple delete than.

Test your machine with anti-rootkit applications. I suggest AVG or Trend Micro RootkitBuster.

Make a HijackThis log to post here or, better, submit the RunScanner log to to on-line analysis.

Immunize your system with SpywareBlaster or Windows Advanced Care.

Check if you have insecure applications with Secunia Software Inspector.

system · 2008-01-01T20:39:44.000Z

[b]Hi Chronos2k…can you run that by me what you did exactly?

Thanks.[/b]

Chronos2k post:18:

Hey, That seemed to work. It found the file, quarantined it and rebooted the system. When I got back on IE there is no sign of the virus. THANKS!!! ;D

system · 2008-01-01T21:32:01.000Z

Update:

Superantispyware does not find the Trojan. It does find a non-existent adware elsewhere ???

system · 2008-01-01T21:48:13.000Z

My C:\WINDOWS\system32\AC3AP.dll[UPX] file is infected by a Trojan Horse detected by Avast Home edition. The name of Trojan Horse is WIN32:BHO-KD[trj].

It was revealed by Avast! in its automatic scan when I started my PC. Avast! suggested action is “move to waste basket”, but when I click on the relevant button Avast! replies “Access denied: I can not process file C:\WINDOWS\system32\AC3AP.dll[UPX].” (access denied).

Then I have run a boot scan, but the scan found the trojan, but was unable to deal with it.

the scan found the infected file in C:\ , but I have another copy of file “system32\AC3AP.dll[UPX].” in E:\ which has also been scanned, but apparently not found infected.

Therefore if I simply copy the apparently non-infected file from E:\ and paste it on C:\ , replacing the infected one, would it solve the problem? Or is it too simple?

Thanks
What shall I do?

oldman960 · 2008-01-01T22:05:37.000Z

That may or may not work, I can’t say for sure.

To submit a file to virustoal, please click on this link

www.virustotal.com

copy and paste the following into the upload a file box (one at a time if more than one file is listed)

C:\WINDOWS\system32\AC3AP.dll

scroll down a bit and click “send file”, wait for the results and post then in your next reply. Post the results here.

You may also want to try the SAS posted at the top of this page.

system · 2008-01-01T22:43:18.000Z

Hi Oldman.

I tried sending the file but get the following message in an otherwise blank white screen:

0 bytes size received

The affected .dll can not be copied or moved so that means it also can not be uploaded.

system · 2008-01-01T22:56:20.000Z

Here is what virustotal gave me.

The answer is in Italian, which is fine for me because it is my mother language.

I hope you will understand nevertheless:

File AC3AP.dll_ ricevuto il 2008.01.01 23:52:01 (CET)
Stato corrente: Carico … in coda attesa scansione finito NON TROVATO INTERROTTO

Risultato:
Carico informazioni server…
Il tuo file è in coda in posizione: 5.
Tempo stimato inizio tra 50 e 72 secondi.
Non chiudere la finestra fino al termine della scansione.
Lo scanner che stava processando il tuo file si è fermato in questo momento, stiamo aspettando alcuni secondi per tentare di recuperare i tuoi risultati.
Se stai aspettando da più di cinque minuti devi rimandare il tuo file.
VirusTotal sta controllando il tuo file in questo momento,
i risultati saranno visualizzati mentre vengono generati.
Formattato Stampa risultati
Il tuo file è scaduto o non esiste.
Il servizio è fermo in questo momento, il tuo file sta aspettando di essere controllato (posizione: ) da un tempo indefinito.

Puoi aspettare la risposta sul web (ricarico automatico) o digitare il tuo indirizzo email nel riquadro qui sotto e premere “richiesta” così il sistema ti invierà una notifica al termine della scansione.
Email:

Antivirus Versione Ultimo aggiornamento Risultato
AhnLab-V3 2008.1.1.10 2007.12.31 Win-Trojan/Bho.84992.E
AntiVir 7.6.0.46 2007.12.31 TR/BHO.agz.16
Authentium 4.93.8 2007.12.31 -
Avast 4.7.1098.0 2008.01.01 Win32:BHO-KD
AVG 7.5.0.516 2008.01.01 Generic9.AJGV
BitDefender 7.2 2008.01.01 Trojan.Spy.Bzub.NGP
CAT-QuickHeal 9.00 2007.12.31 Trojan.BHO.agz
ClamAV 0.91.2 2008.01.01 -
DrWeb 4.44.0.09170 2007.12.31 Trojan.DownLoader.38058
eSafe 7.0.15.0 2008.01.01 -
eTrust-Vet 31.3.5421 2008.01.01 Win32/Kvol!generic
Ewido 4.0 2008.01.01 Trojan.BHO.agz
Informazioni addizionali
File size: 90880 bytes
MD5: 78dc77baf74190269500facd24c738eb
SHA1: b7904100d761fe31c441c5e0674b48f2bb6fd64a
PEiD: -
packers: UPX
packers: UPX

ATTENZIONE: VirusTotal è un servizio gratuito offerto da Hispasec Sistemas. Non esiste garanzia circa la disponibilità e la continuità di questo servizio. Nonostante il livello di identificazione conseguito da multipli motori antivirus sia molto superiore a quello offerto dal singolo prodotto, questi risultati NON garantiscono la sicurezza di un file. Attualmente, non esiste soluzione che offra certezza al 100% sull’identificazione di virus e malware.

oldman960 · 2008-01-01T23:09:37.000Z

@pino-88

It’s definatley infected. I’ don’t know if you can replace it as you suggested. It may be worth a try. It’s also possible SAS will remove it, if you want to try.

Click on this link for download and set up instructions.

http://forum.avast.com/index.php?topic=32338.msg270447#msg270447

Failing that, we can use a different method.

oldman960 · 2008-01-01T23:14:36.000Z

@ dholliday

When you ran SAS did you update and run it in safe mode with these settings?

Under Configuration and Preferences, click the Preferences button.
Then click the Scanning Control tab.

Under Scanner Options make sure the following are checked

CHECK ALL BOXES

Return to the main page by clicking close on that screen. On the main screen, under Scan for Harmful Software click Scan your computer. On the left check C:\Fixed Drive.(and other fixed drives)
Under Complete Scan, choose Perform Complete Scan.
· Click Next to start the scan.

system · 2008-01-01T23:18:46.000Z

Update:

The file crypt3.dll appears to be almost like a phantom. When I tried to email it to VirusTotal the email just sent with the file apparently uploaded and attached but when I looked in Sent Objects the email that was sent did not have an attachment.

So in summary:

SuperAntiSpyware does not find the Trojan
Avast does find the Trojan
Security Task Manager identifies crypt3.dll as being a 92% dangerous file, but cannot delete/move it
Upon Boot scan with Avast with Archive ON Trojan file is found but remains Access Denied
crypt3.dll will not let itself be moved, copied or uploaded. It has no identifiable properties. It has next to zero mentions on the web apart from an ongoing epic saga here:

http://www.bleepingcomputer.com/forums/topic121819.html

We do not yet know:

what Win32:BHO-KD is exactly as I haven’t found any sites that identify it.
how to force ownership of the affected file so that we can quarantine it.
what kind of file crypt3.dll is supposed to be: of what processes/applications it runs from or where it comes from.

system · 2008-01-01T23:20:25.000Z

[i]Hi Oldman…I’ve just now seen yr post so will try SAS in safe and report back.

Thanks.[/i]

oldman post:27:

@ dholliday

When you ran SAS did you update and run it in safe mode with these settings?

Under Configuration and Preferences, click the Preferences button.
Then click the Scanning Control tab.

Under Scanner Options make sure the following are checked

CHECK ALL BOXES

Return to the main page by clicking close on that screen. On the main screen, under Scan for Harmful Software click Scan your computer. On the left check C:\Fixed Drive.(and other fixed drives)
Under Complete Scan, choose Perform Complete Scan.
· Click Next to start the scan.

system · 2008-01-02T17:57:52.000Z

Hallo Oldman,

I have performed the suggested procedure, but the trojan is still there.

My experience is similar to that of dholyday i.e.

SuperAntiSpyware does not find the Trojan
Avast does find the Trojan
Upon Boot scan with Avast with Archive ON Trojan file is found but remains Access Denied

I also tried (unsuccesfully) a low-tech solution by copying a non-infected copy of c:\windows\system32\ac3ap.dll[UPX] from partition e: and replacing the infected file.

have you any idea of what this trojan exactly does? If it simply “spyes” on me there will be no problem: I never process sensible/confidential information on this PC/connection.
it must be connected to Internet explorer because when I start the browser avast pops up with it. So what will happen if I simply stop to use IE and use anoter browser instead? (Opera? what is the most basic one?)

oldman960 · 2008-01-02T18:01:11.000Z

Download ComboFix from Here or Here to your Desktop.

Double click combofix.exe and follow the prompts.

When finished, it shall produce a log for you. Post that log and a HiJackthis log in your next reply
Note: Do not mouseclick combofix’s window while its running. That may cause it to stall.

Click here to download HJTsetup.exe

[*]Save HJTsetup.exe to your desktop.
[*]Doubleclick on the HJTsetup.exe icon on your desktop.
[*]By default it will install to C:\Program Files\Hijack This.
[*]Continue to click Next in the setup dialogue boxes until you get to the Select Addition Tasks dialogue.
[*]Put a check by Create a desktop icon then click Next again.
[*]Continue to follow the rest of the prompts from there.
[*]At the final dialogue box click Finish and it will launch Hijack This.
[*]Click on the Do a system scan and save a logfile button. It will scan and the log should open in notepad.
[*]Click on “Edit > Select All” then click on “Edit > Copy” to copy the entire contents of the log.
[*]Come back here to this thread and Paste the log in your next reply.
[*]DO NOT have Hijack This fix anything yet. Most of what it finds will be harmless or even required.

system · 2008-01-02T18:08:52.000Z

Hi, i have this virus “Win32:BHO-KD (Trojan)”, you can help me please??

what i have to do?? thanks…

system · 2008-01-02T18:18:02.000Z

I have already, main.txt and extra.txt, with Hijack… and next what i do??

oldman960 · 2008-01-02T18:42:19.000Z

gipsyking post:33:

I have already, main.txt and extra.txt, with Hijack… and next what i do??

Please start your own thread and post the logs in it. With more than one person posting logs in the same thread, it will get really confusing.

system · 2008-01-02T18:54:36.000Z

Hi,
I’m very new to the forums, so please bear w/me. I also have the trojan Win32:BHO-KD. I followed the reboot instructions and the message I get is access denied when I try to place it in the chest.
Does anyone have any info on what type of trojan it is, the damage level etc. ANY help and info would be greatly appreciated.
Thanks,
Nico

oldman960 · 2008-01-02T19:19:09.000Z

Welcome to the forum

If you start your own thread by clicking on the “new topic” button at the top of the page. I will give you instructions on removal of this pest.

system · 2008-01-02T20:03:47.000Z

oldman post:36:

Welcome to the forum

If you start your own thread by clicking on the “new topic” button at the top of the page. I will give you instructions on removal of this pest.

I’m not sure if you are ref. to me or not…sorry, I am not familiar w/the protocol on this board. Don’t know which button/topic you want me to start. I thought this was a good place to post my problem since I too have gone through the steps and Avast doesn’t seem to be able to rid my PC of this pest. So,any help anyone can give me would be greatly appreciated.
Thank you in advance.

essexboy · 2008-01-02T20:41:47.000Z

Hi nic I will start a new topic for you with your name and we can work from there

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