It all started with Polymarket.

Recently, I've been researching Polymarket.

Especially the BTC five-minute market.

Automated trading, AI agents, strategy models, momentum detection...

These are all areas I'm very interested in.

It was during this process that I came across polyfil.online.

The website promotes itself as an automated trading system for Polymarket, executing trades automatically through strategy models.

For someone researching automated trading, such a product not only doesn't seem strange but is actually quite reasonable.

This is also the most successful part of the entire scam.

Why did I believe it?

Looking back, I didn't believe them because of the so-called "high returns."

What really let my guard down was the sense of professionalism created by the entire product.

It had:

• A beautifully designed website;
• Complete product introduction;
• Seemingly reasonable trading strategies;
• Continuously updated pages;
• Telegram customer service;
• Constant email replies.

More importantly, it wasn't the same person replying to me.

Different names kept appearing in the emails, making me believe it was a real operating team.

The entire communication process lasted nearly two weeks.

They didn't rush me.

They didn't pressure me to recharge.

Instead, they patiently answered my questions.

Looking back now.

What they were really running was not automated trading.

Buttrust.

The fatal step

Finally, they told me:

The private key would be encrypted, and the platform could not access it.

To me at the time,

this sounded very professional.

It also matched the technical image they had been building.

So,

I handed over the wallet private key.

This was the only truly fatal step in the entire incident.

It was also the step I regretted the most later.

How did the money disappear?

Not long after.

Unauthorized transactions began appearing in my wallet.

Then:

• All wallet assets were transferred out;
• Polymarket could no longer be logged into;
• The official API directly returned:

{  "type": "forbidden error",  "error": "account deleted"}

It was only later when I checked the transaction records on the Polygon chain that I found out.

The whole process:

No blockchain vulnerability.

No wallet vulnerability.

No smart contract vulnerability.

Simply because:

I gave the highest authority of my wallet to someone else.

What is truly terrifying about this scam

Many people, when mentioning Web3 scams,

Their first reaction is:

A crude website.

Poor English.

Absurd yield rates.

But polyfil.online was nothing like that.

It had:

• Professional website design;
• A seemingly reasonable business model;
• Plausible technical logic;
• Long-term trust building;
• Email communication;
• Telegram customer service.

The entire scam wasn't completed in five minutes.

It took nearly two weeks.

That's what made it most dangerous.

My biggest reflection

After being scammed.

I kept asking myself:

Why did I believe it?

Later, I finally figured it out.

It's not them that I believe.

What I believe is:

Automated trading is real.

Polymarket API is real.

The five-minute market is real.

AI analysis is real.

The strategy model might also be real.

So I began to subconsciously think:

This team should also be real.

Only later did I realize.

Technology being valid does not mean the team is trustworthy.

Business logic being valid does not mean the permission design is reasonable.

These are two completely different things.

I always thought I wouldn't be scammed.

Only later did I discover.

I just hadn't yet encountered the scam that was truly meant for me.

Never give out your wallet's private key

If this article can only leave one conclusion.

It is this sentence:

Never give out your wallet's private key.

No matter who it is.

No matter how beautiful the website is.

No matter how professional the customer service is.

No matter how carefully the emails are replied.

No matter how excellent the strategy is.

No matter what they say:

• We will encrypt;
• We cannot access;
• Just for automated trading;
• Just for local execution;

Don't do it.

Once the wallet private key is handed over,

the wallet no longer belongs to you.

Written for those who later search for polyfil.online

If you are now searching for:

polyfil.online

Please stop and ask yourself a few questions:

Why does a truly profitable automated trading need my wallet private key?

Why can't local signing be used?

Why can't WalletConnect be used?

Why can't a solution with fewer permissions be adopted?

Why must users surrender the highest level of permissions?

If a product, from its very design, requires users to hand over their wallet private keys,

then no matter how professionally it is packaged,

it is not worthy of trust.

Conclusion

By the time you read this article,polyfil.online may already be inaccessible.

Perhaps the scammers have already changed the domain, redesigned the website, replaced the logo, and even adopted an entirely new brand name.

But the scam itself rarely changes.

What they truly sell is never an automated trading bot or an AI strategy, but a trust built step by step.Trust.

Websites can be rebuilt.

Domains can be changed.

Customer service can be replaced.

Strategies can be repackaged.

The only thing that never changes is that they will eventually find a way to obtain your highest permissions.

If a project asks you to provide your wallet private key, just walk away.

I hope that in the future, when someone searches for polyfil.online, or searches for a new domain name, they will first see this article, rather than starting to look for answers only after their assets have been transferred away, like I did.

A truly trustworthy product should not require users to hand over their wallet private keys.