URL:Blacklist Warning: Why Avast and AVG Are Blocking Your Site
By Glenn Lyvers · Updated · 6 min read
URL:Blacklist is what Avast and AVG show when the address someone tried to open matches an entry on a blocklist their web shield consults. Read that carefully, because the distinction matters more than it looks: the warning is not saying their scanner examined your pages and found malware in them. It is saying your address is on a list. Something put it there, possibly weeks ago, and the list is what is being enforced now.
That single fact explains nearly every confusing thing about this detection — why it can appear on a site that looks perfectly clean, why it sometimes survives a thorough cleanup, and why the fix involves going somewhere other than your own server.
URL:Blacklist vs URL:Mal: a real difference
These two labels come from the same product family and get used interchangeably in forum threads, but they describe different verdicts. URL:Mal is the generic malicious bucket — the shield concluded the address is serving or leading to something harmful, usually from signatures or crawler observations of the page itself. URL:Blacklist means the address matched a blocklist entry.
The practical consequence is where you spend your effort. A URL:Mal usually points at something currently live on your pages that you can find and remove. A URL:Blacklist may point at something that was live a month ago and is already gone, with only the list entry remaining. Both need your site verified clean. Only one of them is frequently a paperwork problem.
If you saw this on someone else's site
A quick detour, because a lot of people who search this phrase aren't site owners at all. If Avast or AVG blocked a page while you were browsing and you're wondering whether you have caught something: you almost certainly haven't. The web shield blocks the connection before anything loads, so a blocked page is the product working, not evidence of an infection on your machine. There is no "URL:Blacklist virus" to remove from your computer. If the same warning appears on sites you trust, on every site, or in a pop-up demanding payment or a phone call, that's a different problem — scareware imitating a real detection — and that copy of it is worth investigating on your own machine.
The rest of this is for the person who owns the flagged site.
What puts a site on the list
In rough order of how often I see it: a genuine compromise that served malicious JavaScript or a drive-by redirect, even briefly, and got crawled during that window. A conditional redirect that only fires for visitors arriving from search results, which is why the owner can load the site fifty times and see nothing wrong. Spam or phishing pages sitting in a directory nobody created. A compromised mailer sending spam from your domain, which lands you on mail-reputation lists that feed web reputation. And a third-party script — an ad network, a widget, a tracker you embedded years ago — that was itself compromised.
Then there are the cases with no compromise at all. Shared hosting where a neighbor on the same IP earned the listing. A brand-new domain with no reputation history. Aggressive affiliate or shortener redirects. A previous owner's bad behavior riding along with a domain you bought secondhand. These are real, they are worth disputing, and they still deserve a genuine check first: appealing a site that turns out to be infected costs you days and gets you relisted immediately.
Clearing it: clean first, then delist
The order is not negotiable, and getting it backwards is the most common mistake I see.
Verify the site honestly. Load it from a mobile browser, from a private window, and by clicking a Google search result rather than typing the address — conditional malware checks all three. Fetch your homepage with a Googlebot user-agent and read the raw HTML for scripts and iframes you didn't add. Check for .php files in your uploads folder. Run a multi-engine blacklist check as well, because a listing on one vendor usually means listings on several, and you would rather find all of them now than one per week.
Clean completely, including the way in. Remove the injected code, delete the planted pages, and find the entry point. If you skip that last part the infection returns mid-review, and a site that gets relisted immediately after a successful appeal is treated far more harshly the next time. My step-by-step WordPress malware removal walkthrough covers the whole sequence.
Purge every cache. A clean origin behind a poisoned CDN cache still serves the malicious response to a reviewer's crawler. Clear the CDN, the page cache and any object cache before you submit anything.
Then submit the dispute at the source. Avast and AVG take false-positive and re-review submissions through their own forms, and if the listing came from an upstream feed rather than from Avast directly, that source needs its own submission. I keep the current removal and dispute links for every major vendor in one place, because they move constantly.
Why it lingers after the site is clean
Two reasons, and both are ordinary. First, propagation: even after a vendor clears an entry, the change has to reach installed clients, and copies of the old definitions keep blocking for a while. Anywhere from a few hours to several days is normal, and there is nothing you can do to speed it up.
Second — and this is the one that catches people — reputation data is shared and resold. If your listing originated with an upstream feed, clearing Avast's copy doesn't clear the feed, and the feed will simply re-supply it. If a warning comes back a week after a successful appeal, that is usually what happened, not a reinfection. Check the site properly anyway to rule out something that survived the cleanup, then chase the upstream source.
If you'd rather not run this down yourself, blacklist recovery is something I do routinely: verify the site, clean whatever is actually there, and work the delisting queues with each vendor until the warnings are gone.
Common questions
What is the URL:Blacklist virus?
It isn't a virus. URL:Blacklist is a detection name Avast and AVG use when a web address matches an entry on a blocklist their web shield checks, and the block happens before the page loads. If you saw it while browsing, nothing was installed on your computer and there is nothing to remove. If it appears on your own website, it means your address is on a list that needs clearing at the source.
Is URL:Blacklist a false positive?
Sometimes, and genuinely so. Shared hosting IPs, brand-new domains, aggressive affiliate redirects and a secondhand domain's previous owner can all produce a listing with nothing wrong on your site today. But the more common case is a real compromise that has since been partly cleaned, or one that only shows itself to visitors arriving from search. Verify the site properly before you appeal, because appealing while infected gets you relisted and treated more harshly.
How do I remove a URL:Blacklist detection from my website?
In this order: verify the site from a phone, a private window and a search-result click; remove any injected code or planted pages and close the entry point that let them in; purge your CDN and page caches so a reviewer doesn't fetch a cached copy of the infection; then submit a re-review through Avast's and AVG's own dispute forms. If the listing came from an upstream reputation feed, that source needs a separate submission.
How long does URL:Blacklist take to clear?
Once a vendor accepts a re-review, expect a few hours to several days for the change to reach installed clients, since old definitions keep blocking until they refresh. If the listing originated with an upstream feed that also resells the data, full clearance can take longer and may require a separate request to that source. Repeat listings after a failed cleanup take substantially longer than a first-time appeal.
Why does Avast still block my site after I cleaned it?
Usually one of three things: the definition update hasn't propagated to clients yet, the listing came from an upstream feed that is still supplying it to Avast, or your CDN is still serving a cached copy of the infected response even though the origin is clean. Purge every caching layer first, then confirm whether the entry is Avast's own or inherited from another source.
Is URL:Blacklist the same as URL:Mal?
No, though both come from Avast and AVG. URL:Mal is their generic malicious verdict, typically based on what the shield observed on the page itself, and usually points to something live you can find and remove. URL:Blacklist means the address matched a blocklist entry, which may reflect something that was fixed weeks ago and only survives as a list entry. Cleaning is required for both; the second is more often a delisting problem.