This could be due to the websites you visit. If you suspect you have malware on your computer:

you can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista if you don't already have one. Windows 8/10 have antivirus protection built-in.

If it's like the fake FBI/Interpol browser lock page, This add-on can stop such pages; disallow Script Button {web link} The Disallow Script button looks like a letter "M" and the title is the Minus Script, drag and drop the button on a toolbar. If the button is not displayed then nothing operates, except rules for plugins.

i have done a Windows defender anti virus scan and Malwarebytes scan and nothing came up but can't these scans miss threats sometimes?

The website i visited was one ive visited regulary and never had problems, it's a forum for a game i play and many use it, i didnt even click on anything and my Windows defender didnt even flag up to block anything of a threat

Some advertisers have discovered a technique to divert you from a normal page to their site. If you do not already use an ad blocking extension, you could consider that as a layer of your defense. For example:

https://addons.mozilla.org/firefox/addon/ublock-origin/

Like many content-changing add-ons, you may occasionally need to use its button to make an exception for a page to work correctly. Each user needs to find her/his own balance of security and convenience.

Speaking of extensions, an address starting with moz-extension:// is an internal location of a component of one of your add-ons, so that normally is nothing to worry about.

Hi yeah i have adblock plus enabled on my browser

yeah thats why i posted here cuz it said moz-extension://.

so what you think happened and is it anything of concern?

Thanks

Firefox add-ons should not give you big red pop-ups. Have you reviewed your list to make sure nothing strange snuck in?

You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Extensions. Then cast a critical eye over the list on the right side. All extensions are optional. If in doubt, disable.

Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

If you see the moz-extension:// address in your history -- you can use the Library dialog, either:

• Ctrl+Shift+h
• History menu > Show All History

and then use the search in the upper right, or look for the time you started up Firefox -- you can copy/paste it into a reply. Although the first part of the address is randomized to prevent websites from accessing it, the later parts are helpful in tracking down which extension has that page.

Hi, i looked at the extensions and all the ones i am aware of are there, no unknown ones...

i have done virus scan windows defender, microsoft safety scanner and malwarebytes and no threat.

i cleared my history but took note of the moz extension and url of them.

nothing else has appeared since, no idea what to call it or find out whatever it was.

i am just concerned because i kept clicking the x button and close button to get rid of the username/password box thing (no idea what password it was even asking for) and it kept instantly bouncing back (it was infront of the actual pop up website thing), until i just closed all of firefox. im just hoping by clicking the x i didnt activate or download something hidden

Dayne2015 said

i am just concerned because i kept clicking the x button and close button to get rid of the username/password box thing (no idea what password it was even asking for) and it kept instantly bouncing back (it was infront of the actual pop up website thing), until i just closed all of firefox. im just hoping by clicking the x i didnt activate or download something hidden

If it's like the ones I've seen, that dialog did not have any interactivity that could cause a software download. The page keeps reloading the moment the dialog is closed. If you press the Esc key several times in quick succession, that should terminate the cycle by stopping the reload, and then you can close the tab.

ok thanks and the ones that do this are - if you click the x or close button for example, do you see the download starting as if you just clicked ok to download or does it happen literally like invisible?

i ran another scan with microsoft windows malicious software removal and no threats came up, so thats 4 different scans i've run

Dayne2015 said

thats 4 different scans i've run

Malwarebytes is the only malware scanner you listed. The others are virus scanners.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.

FredMcD said

Dayne2015 said

thats 4 different scans i've run

Malwarebytes is the only malware scanner you listed. The others are virus scanners.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.

in the link you provided it says Microsoft safety scanner is one of the scanners used for malware

Dayne2015 said

ok thanks and the ones that do this are - if you click the x or close button for example, do you see the download starting as if you just clicked ok to download or does it happen literally like invisible?

If you have Firefox set to ask you where you want to save a download, of course it will be more obvious, but even if Firefox auto-saves a download, you'll see the download arrow on the toolbar animate to indicate completion and the download will be listed. This is for normal file pushes, and not what plugins can do; plugins can bypass the normal browser mechanisms.

jscher2000 said

Dayne2015 said

ok thanks and the ones that do this are - if you click the x or close button for example, do you see the download starting as if you just clicked ok to download or does it happen literally like invisible?

If you have Firefox set to ask you where you want to save a download, of course it will be more obvious, but even if Firefox auto-saves a download, you'll see the download arrow on the toolbar animate to indicate completion and the download will be listed. This is for normal file pushes, and not what plugins can do; plugins can bypass the normal browser mechanisms.

ok is there anyway to see what my plugins are doing/downloading?

you said earlier that advertisers have found a way to divert my page to their website... i do have adblock plus plugin/extension on my firefox, have for years, is it possible one just got through somehow and it was a rarity? i can't remember the last time it happened and hasnt happened again since

or have these advertisers found a way to get round adblock plus or something?

Dayne2015 said

ok is there anyway to see what my plugins are doing/downloading?

I don't know.

you said earlier that advertisers have found a way to divert my page to their website... i do have adblock plus plugin/extension on my firefox, have for years, is it possible one just got through somehow and it was a rarity? i can't remember the last time it happened and hasnt happened again since or have these advertisers found a way to get round adblock plus or something?

I've never been redirected to one of these pages, I've only seen the ones users have posted links for, but as far as we can tell, users are just browsing normally when suddenly a new tab pops up. If it's not from an ad, perhaps they were on an evil site??

Redirect Control 0.1.2 This add-on enables the user to allow or deny redirects from web pages. You can also create rules to allow redirects that you approve of.