I have Avast Free Antivirus 10.4.2233. The Web Shield is blocking access to many legitimate websites - saying the certificate is invalid - even those added to ‘Exclusions’. An example is https://www.eir.ie/ - although this has been added to Exclusions.
This seems to happen only in Firefox but not in Chrome or IE.
[i][i]P.S Since posting the above the behaviour has changed - the blocking notice appears but the webpage still loads??
- OS…? (32/64 Bit…? - which SP/Build…?)
- Other security related software installed…?
- Which AV(s) did you use before Avast…?
Windows XP SP3 32 Bit - Superantispyware Free - Used AVG Free up to about three years ago,
I am going over your website now and I am happy to find that there are no vulnerable javascript libraries found up.
This however came immedeately blocked by an scriptblocker extension: uMatrix has prevented the following page from loading:
-https://lptag.liveperson.net/tag/tag.js?site=36014936
I detect Possible Frontend SPOF from:
ajax.googleapis.com - Whitelist
(67%) -
(67%) -
cdnjs.cloudflare.com - Whitelist
(67%) -
(66%) -
Tracker SSL 85% of trackers let through - Unique IDs about your web browsing habits have been insecurely sent to third parties. For me those were 7 parties: -www.eir.ie
-Google
-cdnjs.cloudflare.com
local.adguard.com (because of my Adblocking software)
-www.googletagmanager.com
-LivePerson
www.mustbebuilt.co.uk www.mustbebuilt.co.uk (because of my BuiltWith extension)
AOS flags one web analysis tracking for googletagmanager and Ghostery also for Liveperson.
See tracking the trackers report attached (for all the scripts you use)
Re: https://www.threatcrowd.org/domain.php?domain=2404210.fls.doubleclick.net
See no issues for that website, but for the IP I see:
http://www.anti-fraudscam.com/www-studyhub-ie_fraud_scam_report.html
polonus (volunteer website security analyst and website error-hunter)
I am 79 and a relative computer novice - I’m afraid your reply is almost completely unintelligible to me!
You are welcome, Tobur,
I just wanted to tell you that the code on that website has some vulnerabilities and some external adware links (use an adblocker visiting that site), but there is no active malware there. So if you have a problem visiting the website then it may be your computer at fault. The SPOF detections mean that those scripts could make that webpage load slower as should be.
Trackers means code that goes from your computer behind your back to be shared with third parties when in an insecure way. Mostly this happens unknown to you. Telemetry info sharing is a user’s privacy problem or has the possibility to grow into one.
I can understand that the technicalities are a bit incomprehensible for those that are not into this cold reconnaisance website security scanning and web-error hunting, but website owners and hosters and IT may grasp what I am on about. Sorry that I am only 67 years old, so it also meant for the elder tech-savvy 
and it is keeping my grey cells busy and trained ;D
polonus
Thanks for reply - I am 79 from the neck down but about 26 from the neck up !!
The Webpages in ‘Exclusions’ are now loading but the blocking notice still pops up - as it does on some other legitimate sites. This is quite annoying - I sometimes have to disable Web Shield to access a site - is there any way around it??
Hi,
Can you post a printscreen of the detection?
If this is happening only in certain browser, it might be that the browser is not configured correctly - you may want to reinstall it or restore default settings.
Seems to happen in Firefox only - Printscreen jpg. attached
That sub domain does not resolve: http://toolbar.netcraft.com/site_report?url=http://ssl334328.cloudflaressl.com *
No valid host header found - CloudFlare Ray ID: 23c986fb6f350c29 see: http://toolbar.netcraft.com/site_report?url=http://104.20.70.54 ssl-cert: Subject: commonName=ssl324049.cloudflaressl.com
For * see: https://www.robtex.net/en/advisory/dns/com/cloudflaressl/ssl334328/
The detection or error is being confirmed here: http://mxtoolbox.com/domain/ssl334328.cloudflaressl.com/
4 Problems
Category Host Result
dmarc cloudflaressl.com Missing or Invalid Record
dns cloudflaressl.com SOA Serial Number Format is Invalid
dns cloudflaressl.com SOA Expire Value out of recommended range
spf cloudflaressl.com No records found
tls-nextprotoneg:
| spdy/3.1
|_ http/1.1 TLS randomness
polonus
Thanks for your reply -I said your previous reply was “almost completely unintelligible” to me - this time I leave out the “almost”!!
Is there (in simple terms) a way to avoid the regular popping up of the blocking notice?
Hi Tobur,
First we have to await a reply by one of Avast Team Members (as we here are only volunteers with some relevant knowledge), one of them might give you the recipee to solve this annoyance or cleanse it. The unintelligable part of the message comes down to the fact there is something wrong with the SSL Certificate of that specific sub-domain of cloudflaressl.com. From the mxtoolbox scan report you can conclude that they haven’t got their act together - with records and serial numbers, a hick-up or error or rather sloppy service, maybe they underpay their IT staff on the work-floor a tad ;D Jokes apart, there are more problems with bulkhosters like these you experience here , as they like to cash in but do not give much pro-active support in return ;D
polonus
Disable HTTPS-scanning in the web shield.
Or just have Asyn answer 
Thanks! - Reply from Asyn was what I was looking for since first posting.
I have disabled HTTPS-scanning in the web shield and this seems to have worked.
Quote: If you can’t explain something in a few words, try fewer. ~Robert Brault,
You’re welcome.
I’ve been an Avast user ( both PC and Mobile ) for over 3 years. Until recently I’ve had zero problems. But ---- Avast on my PCs is now slowing down the boot and blocking or interfering with EVERY legitimate site! My PC now takes over 6 minutes to complete boot, and as soon as I go to Internet ( Firefox ), every bookmarked site that I use regularly is slowed to an absolute crawl by Avast’s interference! Normal sites such as Amazon, my own web banking, my credit card sites, etc. are taking as much as 2 minutes to load, if they load at all. This is now worse than the old dialup 56k modem era. I placed an “exception” to get my Yahoo home page to load, but do I have to enter exceptions for EVERY SITE that I use? Yes, I can disable the web shield and I have, but that should not be needed. I’ve read that Avast is supposedly “aware” of the problem and was to issue an “update”. If so, where is it and why is it even needed for standard trusted use? If this continues much longer I will cancel my annual subscription and demand a refund.
If you’re looking for help in solving your problem, give us some information that will help us solve your problem.
If you’re simply looking for a refund, contact Avast directly:
http://support.avast.com/support/tickets/new
Asyn and polonus - I get the same pop-up message as Tobur above when I visit the Wall Street Journal website www.wsj.com –
“Avast Web Shield has blocked access to this page because the following certificate is invalid: ssl334328.cloudflaressl.com”
Also, the little blue circle in the tab in Firefox does not stop spinning when I get that message.
As far as I can see, it’s just when I go to the Wall Street Journal.
My PC is XP Pro SP3 32-bit. My browser is Firefox 41.0.2. Also, my Firefox has the add-on Https Everywhere. Is that the cause?
I don’t understand much about certificates, so is Https Everywhere forcing the browser to go for a certificate and somehow that forcing is bad?
Asyn’s suggestion to set Avast to stop checking in https doesn’t feel right. Feels like I’d be opening a security hole.
What do y’all think? Thanks.