This was true for my use of Gramblr – and was discovered by many others too:

Gramblr is Malware, Gramblr Pauses Youtube History
byu/Cinobite insocialmedia

In the summer of 2019, the Gramblr web site has gone offline and the program has disappeared.

I had used Gramblr to upload still photos to Instagram, from my PC. Gramblr also had a feature that let you buy “Likes” (and get some for free from other Gramblr users) suggesting their business model was to sell Likes (but that was not their business model). I only used the program to upload photos – buying Likes is stupid since it mostly acquires spammy accounts that do not engage with the Instagram community, which in turn, results in the “Instagram Algorithm” showing your photos to fewer people.

When Gramblr was installed I discovered the oddity that my Youtube viewing history had been disabled. Gramblr did that behind the scenes because each time you uploaded a video to Youtube, the program secretly played a Youtube video. In fact, the Gramblr business model was to sell Youtube views to people who wanted to hack the Youtube visibility and recommendation algorithm.

From a Youtube perspective, the views looked legitimate as they came from PCs all over the world, viewing just one video at a time.

When I saw the Youtube history was turned off, I turned it back on. Then, occasional videos that I never watched would appear in my viewing history. Eventually, Gramblr would again turn off viewing history so this would not be visible.

Gramblr could do this because they used your GMail account to log in to their system. Was never clear why this was necessary – in fact, it was only necessary to implement their malware viewing business on Youtube.

I removed Gramblr and the viewing of videos stopped, and my viewing history no longer became disabled.

If you search for Gramblr online, you’ll find sites saying it tests as “virus” free. Of course it does. It’s not a virus – the users who install it are the virus that spreads its attack platform on line. Gramblr was a user installed botnet, design for selling fake views on Youtube. The Instagram photo upload was an extremely clever way of getting users to install the malware. (Instagram created this opportunity for malware by not offering their own PC upload capability, which every one wants to have.)

When ever you find “free software” online, you need to ask: What is the business model of the company that is distributing this “free software”?

Most of the time, their website never says anything about the business model. In fact, they have no offices or any information about who they are. If you cannot tell how they make money, you should assume the purpose of the software is malware-related.

As of the summer of 2019, Gramblr has disappeared. It’s secret back end operation was likely shut down by Youtube, killing off their revenue stream.