Bot and API Security: Your Telegram Bot Is Online 24/7, and So Are the Attackers

The moment you deploy a Telegram, Discord, or WhatsApp bot — or expose an API for it — you have opened a door to the entire internet. That door does not close at night. It does not take weekends off. And most of the traffic knocking on it is not your users.

That is not a scare tactic. It is just the current shape of the web.

In its 2025 Bad Bot Report, Imperva reported that for the first time in a decade, automated traffic overtook human traffic, reaching 51 percent of all web traffic. Bad bots specifically — the malicious kind — made up 37 percent of all internet traffic, up from 32 percent the year before.

Two things made this worse fast. First, AI lowered the barrier to building bots, so even low-skill attackers can now launch high volumes of attacks. Imperva noted that simple, high-volume bot attacks grew to 45 percent of all bot attacks in 2024. Second, attackers increasingly aim at APIs on purpose: 44 percent of advanced bot traffic was directed at API endpoints.

Chat bots and the APIs behind them are an attractive target for a few very practical reasons.

They are always reachable. A bot listens for messages around the clock, which means an attacker can probe it continuously with zero friction.

They often trust input too much. A bot command is just text, and if that text flows into a database query, a shell command, or an AI prompt without validation, it becomes an injection point.

They hold valuable tokens. Your bot token is effectively the keys to the bot, so if it leaks, an attacker can impersonate your bot entirely until you notice and rotate it.

They can be turned into a weapon. An unprotected bot or API can be abused for spam, credential stuffing, or as a relay in a larger attack — all under your name and on your infrastructure bill.

It helps to be concrete. Here is what "attack" actually looks like for a typical bot or API:

Command abuse: someone scripts thousands of requests to a command that triggers expensive work, and your service slows to a crawl or your costs spike.

Prompt injection: if your bot pipes user text into an AI model, a crafted message can hijack the model's behavior and make it leak data or do things it should not. Prompt injection sits at the very top of the OWASP Top 10 for LLM Applications.

Credential stuffing: bots try huge lists of leaked email and password pairs, betting that people reused a password somewhere. Verizon's 2025 DBIR found this made up about 19 percent of all authentication attempts on a typical day — and because these attacks try each stolen credential just once, they slip right past basic per-IP rate limits.

Scraping: bots pull your data faster than any human could, whether that is user info, pricing, or content you did not intend to hand out in bulk.

The defenses are well understood. You do not need to reinvent anything — you need to put the standard layers in place and keep them tuned.

Rate limiting and throttling per user and per IP, so no single source can flood a command or brute-force a login. Webhook signature validation for platforms like Telegram, Discord, Slack, and WhatsApp, so your bot only acts on requests that genuinely came from the platform. A WAF with API-specific rules, so common injection and abuse patterns get blocked before they reach your logic. Anti-abuse filters on bot commands, so expensive or sensitive actions cannot be triggered in bulk. Token leak monitoring for your bot and API tokens, with automatic alerting and rotation the moment one is exposed. And input sanitization — which matters especially when user text feeds an AI model.

Put together, these turn an open door into a controlled one. Legitimate users barely notice. Bots hit a wall.