invalid file signature

Avast Free Antivirus / Premium Security
1

I downloaded AVAST free edition and could not update due to invalid file signature. I have no idea what that means. I searched these forums and surmised that the down load was corrupt.

I un-installed that version which I got on C-net because one of the posts I read said to get it directly from AVAST. I tried to redownload directly from AVAST and was redirected to c-net (twice).

I reinstalled the free version, was again told it needed to be updated and upon trying to update was told update failed due to invalid file signature. I still do not know what that means. The program will not update either. I have since uninstalled that version as well.

I know you want the version # and other data but, well, it was deleted.

Can you tell me how to get an actual working AVAST free program? Or could you tell me what I am doing wrong? Thanks.

2

Try again here http://filehippo.com/download_avast_antivirus/

remeber that you must uinstall any other AV you are using before installing avast!
it is also recomended to run a removal tool to clean out all leftovers
can be found here http://uninstallers.blogspot.com/

3

Hello rgood and welcome: Please follow Pondos’s suggestion.

Here are detailed instruction to follow for a ‘Clean Install’ of Avast.

Please Download the latest version of Avast, 5.0.677 http://files.avast.com/iavs5x/setup_av_free_eng.exe (English only) and save it to your hard drive where you can access it easily.
Then download the Avast Clean up Utility http://www.avast.com/uninstall-utility and save it to your hard drive where you can access it easily.
Please go to Start/Control Panel/Add and Remove Programs and choose Avast and click Remove and then Uninstall. Once the uninstall process is completed, Reboot your computer and when up and running, Reboot again into ‘Safe Mode’ and find the (aswClear v5) download you saved to your hard drive and run the Clean up tool. Make sure you first choose the version you want to cleanup and then run the tool, your computer will automatically reboot. Once up and running in Normal Mode, Install the latest version of Avast you saved to your hard drive and Walla! All should be fine. Please remember you need to choose the version in the Clean up tool that you have had installed on your system.If you have any problems please feel free to let us know.

4

Followed all the steps. Now instead of getting the “invalid file signature” after four minutes of attempting the update I get it after one minute.

Any other options?

5

Obviously something is conflicting with the process.
Could you please provide further information as it may assist us in resolving the issue.
What OS are you using? What version of Avast did you have installed when asked to update? What other Security software do you have installed and running on your system?
Thanks :slight_smile:

6

What OS are you using? What version of Avast did you have installed when asked to update? What other Security software do you have installed and running on your system?

Windows XP Home. Avast 5.0.677. No other security software.

7

Incidently, why would a new program require updating within minutes of installation anyway? I thought I read in the forum that by downloading directly from AVAST the program was up to date.

8

There are sometimes 2 virus definition updates daily:
Virus update history in year 2010
http://www.avast.com/virus-update-history-2010

9

@ rgood,

Most security software needs updating upon installation to have current definitions…this is normal.

The important information we need from you for us to help you is the following:

  1. What is your OS, 32 or 64-bit?
  2. What other security software do you currently have or did you have in the past on this machine including:
  • Antivirus (AV)
  • Firewall (FW)
  • Trial versions of AV, FW and other security programs
  • Other security software
  • If they were in the past, how did you remove them (the vendor’s uninstaller’s tool or another way)?

The reason we ask is because remnants of software can conflict with trying to install new security software, like Avast. Thank you.

10

Okay, how do I know the 32 or 64 Bit answer?

The only AV installed at present is the AVAST I downloaded a few days ago.

I used to have AVG and used the AVG uninstaller to rid myself of that.
It would not let me configure manual updates.

I tried to download MS Security Essentials. It ran but would not update. See a theme? I used their uninstaller as well.

I can download AVAST, but I get the invalid signature message upon an update attempt. I also tried to scan with that program and it ran for three hours scanning less than 1%.

11

http://support.microsoft.com/kb/827218

12

If you do not know if you are running 64 bit then you are running 32 bit.

You can not run MS Security Essentials with avast! as it conflicts.

13

Okay its 32 bit. I uninstalled Security Essentials long before I installed AVAST.

14

Welcome to the forums, rgood. :slight_smile:

Here is the link to download directly from the avast site and let us know how it goes.

http://www.avast.com/support

Use the “Download Now” link right under the avast! Free Antivirus.

15

First, make sure you got rid of all remnants of the prior AV’s on your machine, please run these uninstallers one at a time, and reboot in between each of them:

AVG Uninstaller Tool: http://www.avg.com/us-en/download-tools, reboot.
MSE Uninstaller Tool: http://support.microsoft.com/kb/2435760/, reboot.

You didn’t mention your firewall (FW). Do you use a FW?

Next, uninstall and do a clean install of Avast:

  1. Save a copy of newest version of Avast (5.0.677) and save it to your HDD:
    Free – http://files.avast.com/iavs5x/setup_av_free_eng.exe
  2. Download the Avast Uninstall Utility, aswClear5.exe http://www.avast.com/uninstall-utility and save it to your HDD.
  3. Disconnect from the Internet at this time.
  4. Go to Control Panel and uninstall Avast through Add/Remove Programs if possible and reboot.
  5. If Step 4 fails, boot into Safe Mode (hit F8 repeatedly) and run the Avast Uninstall Tool. Uninstall Avast 5.0 at this time in Safe Mode.
  6. Reboot.
  7. Install the newest version of Avast and reboot.
  8. Get Internet access and register your copy for Free:
    Free – http://www.avast.com/registration-free-antivirus.php
  9. Update the Avast definitions.

If the uninstall/clean install of Avast fails to fix your problem, please check your computer for malware with Malwarebytes’ Anti-Malware (MBAM) since malware can sometimes prevent AV’s from installing properly.
· Download free http://www.malwarebytes.org/ (the blue button) for an on-demand scanner.
· Double Click mbam-setup.exe to install the application.
· After install, click update so you have latest database before scanning.
· Under Settings:
o General: Automatically Save File After Scan Completes is checked off
o Scanner Settings: Check all boxes
o Updater: Download and install update if available is checked off
· Once the program has loaded, select “Perform FULL Scan”, then click Scan.
· The scan may take some time to finish, so please be patient.
· When the disinfection scan is complete, a log will appear in Notepad and you may be prompted to Restart. (See Extra Note).
· Click the “remove selected” button to quarantine anything found. You will find the infection details under the Quarantine tab.
· The log is automatically saved by MBAM and can be viewed by clicking the Logs tab in MBAM.
· Copy & Paste the entire report in your next reply.

Let us know if these solutions fix your problem. Thank you.

16

Ran uninstall on AVG and Security Essentials.

Ran AVAST uninstall utility.

Installed AVAST, again.

Same results. Invalid file signature.

Ran Mbam full scan:
Malwarebytes’ Anti-Malware 1.50.1.1100
www.malwarebytes.org

Database version: 5378

Windows 5.1.2600 Service Pack 3
Internet Explorer 8.0.6001.18702

12/22/2010 5:52:50 PM
mbam-log-2010-12-22 (17-52-44).txt

Scan type: Full scan (A:|C:|D:|)
Objects scanned: 187737
Time elapsed: 38 minute(s), 33 second(s)

Memory Processes Infected: 0
Memory Modules Infected: 0
Registry Keys Infected: 0
Registry Values Infected: 0
Registry Data Items Infected: 0
Folders Infected: 0
Files Infected: 2

Memory Processes Infected:
(No malicious items detected)

Memory Modules Infected:
(No malicious items detected)

Registry Keys Infected:
(No malicious items detected)

Registry Values Infected:
(No malicious items detected)

Registry Data Items Infected:
(No malicious items detected)

Folders Infected:
(No malicious items detected)

Files Infected:
c:\documents and settings\owner\local settings\temporary internet files\content.ie5\enmuop8v\profile1[1].gif (Extension.Mismatch) → No action taken.
c:\documents and settings\owner\local settings\temporary internet files\content.ie5\enmuop8v\right-gutter-bkg[1].gif (Extension.Mismatch) → No action taken.

Quarantined those files.

While the scan was running I got a pop-up that said the firefox file was corrupt, and to run scan disk.

17

MBAM said “No action taken” therefore the infection is still in your machine, so how did you quarantine it? Did you update MBAM again and run it again to quarantine it? This would be the only way. If you deleted it, this is not the same as quarantine. Please clarify what action you took with these infections…look in the MBAM “Log” tab to see what is there and report back. Thank you.

I’m assuming you rebooted in between doing all the uninstalls of AVG and MSE, and Avast, then did the clean Avast install…correct? When did you get this FF pop-up (file corrupt)? What scan did you run? An Avast scan? Which one and what did it report (please be specific with exact file name or give a screen shot).

Are you being redirected to other web sites when online? How is your machine acting now? Is Avast working properly now? If it is, please make sure your Avast definitions are up to date and run an Avast boot-time scan and report back the results.

After this, check the information on the first post of this thread under Virus/Worms for you to check your machine for malware: http://forum.avast.com/index.php?topic=53253.0.

Follow the directions of the OTL logs (save them as ANSI and not Unicode). When the OTL scan completes, it will open two notepad windows. OTL.Txt and Extras.Txt. Update MBAM and rescan (Quick Scan). Post the MBAM log here and the two (2) OTL log as an attachment (Additional Options > Attach > Browse (the logs will be on your desktop > Post). I will review the logs and if needed refer you to our Certified Malware Expert.

Please let me know if you have any questions. Thank you.