My first guess is that you have possibly inadvertently overwritten the desired history. Immediately export a manual backup. You can then safely try to see if the autosaves have still retained any more useful information. ( see my post in the thread "Bookmarks box will not show up and I cannot save new bookmarks."

What is missing.

• Your History, as in list of web pages visited (and so obviously those webpages are downloaded)
• Your Downloads, as in specific saved files ( which will go to some chosen or default folder/directory) and you are probably more concerned with the files themselves rather than merely any listing of them.

The History will be kept for a certain period of time, then deleted, there are options to extend that. There are also backup snapshot type copies available. It is not too late to suggest it is possible to export the history etc as a manual backup at least it will enable you to recover from any accidental overwrites.

I usually try to link to Mozillazine or Firefox kb articles, but this Wiki with a diagram is a good introduction about places.squlite and Firefox History

Thanks, John99,

What is missing is the list of (downloaded) files. The files themselves are OK, so the damage is arguably not that much. I relied on the list for checks e.g. for files already visited.

I made a manual backup of the downloads.sqlite, as soon as I realised I had a problem. I viewed the backup offline with a standalone sqlite browser: only three files show up.

Was the history deleted automatically? Then wouldn't it delete just the oldest entries, and not almost everything, including yesterday's downloads?

I think the original list should be there somehow, seeing that my downloads.sqlite is large (over 2Mb). So maybe it's just a small part of the database that's corrupted.

BTW, that happened the same evening that I had a rather primitive maleware attack: an exe file written into Temp directory, and a process in memory (pretending to be MS Security Essentials) that called this exe file. [I run Vista]. I deleted the.exe file. I suspect there is possibly more than just coincidence between this and my truncated downloads.sqlite.

The Wiki link is a good one, thanks.

As you say it sounds like it is the malware covering its tracks that is the problem, and if the downloads.sqlite is ca 2MB it is listing more than a couple of files, more like thousands. (Unless most of that is

• junk eg just a multiple pass erase block
• or further malware ? !! - have you scanned the file )

I do not think I can be any help, but two thoughts

1. Can you examine the full file ?
   your sqlite browser would seem to be the tool to investigate, but as presumably that only shows part of the file why not try it in a text / hex editor instead. You may get lucky and find if you hack out a line immediately after where the sqlite browser ceases to display it that you get useful information. (it may just contain a premature end of file) You can also obtain freeware sqlite editors if you then want to work on re-creating it.
2. The downloaded files will be in folders create a text list from them
   use the dos equivalent 'DIR' command on the folders and pipe the result into a file, either a separate file for each folder or append the lot in one file, give the file a .txt extension and use as a searchable list, or import into a database program of your choice.

Hopefully someone ele will come up with a better solution.