How to check the security of a bot

Checking the security of a Telegram bot involves verifying its permissions, reviewing its source code or developer reputation, analyzing its data handling practices, and monitoring its behavior over time. A compromised or malicious bot can leak sensitive data, spam your channel members, or even take control of your group. Taking a few minutes to audit bot security before granting it access can save you from serious headaches later.

Why Bot Security Matters

Telegram bots operate through the Bot API and can be granted significant permissions — from reading every message in a group to deleting content, banning users, and managing channel posts. When you add a bot to your channel or group, you are essentially giving a third-party application access to your community.

Unlike human administrators, bots run automated code that executes 24/7. A single vulnerability in a bot's code or infrastructure can expose your entire community. Bots have been used in attacks ranging from phishing schemes to mass data harvesting of group members' phone numbers and usernames.

The Real Risks

  • Data harvesting: Malicious bots can silently collect usernames, user IDs, message content, and metadata from every member in your group.
  • Token theft: If a bot's token is leaked, anyone can impersonate that bot and perform actions on its behalf in your channel.
  • Spam and phishing: Compromised bots can send malicious links to all group members before you even notice.
  • Permission escalation: A bot granted admin rights can modify group settings, remove other admins, or delete message history.

Step-by-Step Security Audit

Step 1: Verify the Bot's Identity

Before adding any bot, confirm it is the legitimate version and not a clone:

  1. Check the bot's username carefully — scammers create bots with names like @GroupHelpBot vs @GroupHeIpBot (with a capital "I" instead of lowercase "l").
  2. Look at the bot's profile for a verified checkmark if the developer is an official entity.
  3. Visit the bot's description and check for a link to the developer's website or GitHub repository.
  4. Search for the bot's name on Telegram's official bot directory or trusted review sites.

Step 2: Review Permissions Before Granting Access

When adding a bot as an admin to your channel or group, Telegram lets you configure its permissions granularly. Follow the principle of least privilege:

  1. Open your channel or group Settings → Administrators → Add Administrator.
  2. Select the bot and review each permission toggle:
    • Change Channel Info — Does the bot need this? Usually no.
    • Post Messages — Only enable if the bot needs to publish content.
    • Edit Messages of Others — Rarely needed; disable by default.
    • Delete Messages — Enable only for moderation bots.
    • Invite Users via Link — Disable unless the bot manages invitations.
    • Manage Video Chats — Disable unless specifically needed.
    • Ban Users — Only for anti-spam or moderation bots.
    • Add New Admins — Almost never enable this. A bot with this permission can escalate its own privileges.
  3. Save and document which permissions you granted and why.

Important: Never grant Add New Admins permission to a bot unless you fully trust the developer and have audited the source code. This is the most dangerous permission a bot can have.

Step 3: Investigate the Developer

A trustworthy bot typically has a transparent developer behind it:

  • Check for open-source code. Bots with public GitHub repositories (e.g., github.com/developer/bot-name) are more trustworthy because anyone can audit the code. Look for recent commits, active issue tracking, and a reasonable number of stars.
  • Look for a privacy policy. Reputable bots like @Combot or @ChatKeeperBot have published privacy policies explaining what data they collect and how they store it.
  • Research the developer. Search for the developer's name or company. Check how long they've been active in the Telegram bot ecosystem.
  • Check the bot's age. Use BotFather or community databases to see when the bot was created. A bot created yesterday claiming millions of users is suspicious.

Step 4: Test in a Sandbox Environment

Never add an untested bot directly to your main channel with 50,000+ subscribers. Instead:

  1. Create a test group or test channel with no real members.
  2. Add the bot to this test environment.
  3. Grant it the same permissions you plan to use in production.
  4. Interact with the bot for several days — send commands, test features, and monitor its behavior.
  5. Check if the bot sends unexpected messages, makes API calls you didn't authorize, or behaves differently than documented.

Step 5: Monitor Network and API Behavior

For technically advanced users or channel owners managing high-value communities:

  • Check the bot's webhook or polling setup. If you control the bot, verify its webhook URL points to a secure HTTPS endpoint.
  • Review API logs. If you're running your own bot using a framework like python-telegram-bot or telegram-bot-ruby, enable logging to track every API call the bot makes.
  • Use BotFather to rotate tokens. Send /revoke to @BotFather periodically to generate a new token, especially if you suspect a breach.
  • Audit third-party integrations. If the bot connects to external services (databases, analytics platforms, webhook receivers), verify those connections are encrypted and authenticated.

Step 6: Check for Known Vulnerabilities

  1. Search for the bot's name combined with keywords like "vulnerability," "hack," "data leak," or "scam" on Google and Telegram search.
  2. Check security advisory databases if the bot is open source.
  3. Look for user complaints in Telegram groups dedicated to bot reviews.
  4. Visit platforms like tgchannel.space to see how channels using this bot present their content publicly — a well-managed web presence often correlates with responsible bot usage.

Securing Your Own Bot

If you are a bot developer, here is how to keep your bot secure:

  • Never hardcode your bot token. Use environment variables (BOT_TOKEN) or encrypted configuration files. A token like 123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11 leaked in a public Git commit can be exploited within minutes.
  • Enable webhook with a secret path. Instead of /webhook, use something like /webhook/a3f8b2c9d1e4 to prevent unauthorized requests.
  • Validate all incoming updates. Check that the update object comes from Telegram's IP ranges (149.154.160.0/20 and 91.108.4.0/22).
  • Use HTTPS exclusively. Telegram requires HTTPS for webhooks, but also ensure your internal API calls and database connections are encrypted.
  • Implement rate limiting. Protect your bot from abuse by limiting how many commands a single user can execute per minute.
  • Keep dependencies updated. Regularly run bundle audit (Ruby), npm audit (Node.js), or pip-audit (Python) to check for known vulnerabilities in your bot's dependencies.

Tips & Best Practices

  • Audit quarterly. Set a calendar reminder to review all bots in your channels every three months. Remove any bot you no longer actively use.
  • Use separate bots for separate tasks. Instead of one "super bot" with all permissions, use dedicated bots — one for moderation, one for analytics, one for posting. This limits the blast radius if one is compromised.
  • Keep a permission log. Maintain a simple spreadsheet documenting which bots have access to which channels and what permissions they hold.
  • Watch for unusual activity. A sudden spike in deleted messages, unexpected bans, or new posts you didn't authorize may indicate a compromised bot.
  • Rotate tokens after team changes. If a developer or admin who had access to your bot token leaves your team, immediately regenerate the token via @BotFather.
  • Back up your channel content. Use services like tgchannel.space to maintain a public web archive of your channel content, so even if a bot deletes posts, you have a recoverable copy.

Common Mistakes

Mistake 1: Granting all admin permissions by default
Why it's wrong: Many channel owners simply toggle all permissions to "on" when adding a bot, because it's faster. This gives the bot far more access than it needs.
How to avoid: Start with zero permissions and enable only what the bot explicitly requires to function. Test after each permission change.

Mistake 2: Using bots from unverified sources
Why it's wrong: Bots shared in random Telegram groups or forums may contain malicious code designed to harvest data or hijack your channel.
How to avoid: Only use bots from developers with a public track record, open-source code, or recommendations from trusted community members.

Mistake 3: Never rotating the bot token
Why it's wrong: If your token was ever exposed — even briefly in a log file, screenshot, or debug message — an attacker could still be using it months later.
How to avoid: Rotate tokens via @BotFather → /revoke at least once every few months, and immediately after any suspected exposure.

Mistake 4: Ignoring bot update logs
Why it's wrong: Without monitoring, you won't notice if a bot starts behaving differently after a developer pushes a malicious update.
How to avoid: Subscribe to the bot developer's changelog or GitHub releases. Test updates in a sandbox before applying them to production channels.

Mistake 5: Sharing bot tokens across multiple projects
Why it's wrong: If one project is compromised, all channels using that token are affected.
How to avoid: Create a separate bot (and token) for each channel or project using @BotFather.

Frequently Asked Questions

Can a bot read private messages in my channel?
Bots can only read messages in channels and groups where they have been added as members or administrators. They cannot access users' private chats unless a user initiates a direct conversation with the bot. In channels, a bot with admin access can read all posted messages.

How do I know if a bot's token has been compromised?
Watch for unexpected bot behavior — messages you didn't send, settings changes you didn't make, or users reporting spam from your bot. You can also use @BotFather's /mybots command to check the bot's webhook URL and verify it points to your server, not an attacker's.

Is it safe to use free bots for channel management?
Many free bots are perfectly safe and well-maintained (e.g., @GroupHelpBot, @Combot). However, "free" sometimes means the bot monetizes through data collection. Always check the privacy policy, and if no policy exists, treat the bot with extra caution.

What should I do if I suspect a bot is malicious?
Immediately remove the bot from all your channels and groups. Revoke its admin permissions before removing it. If you control the bot, regenerate the token via @BotFather. Then review recent channel activity for any unauthorized changes, deleted messages, or added/removed members. Report the bot to Telegram via @BotFather or Telegram's in-app reporting feature.

Can I audit a bot's code if it's not open source?
You cannot directly audit closed-source bot code. However, you can monitor its network behavior using proxy tools, observe its actions in a test environment, and review its data handling by checking what information it requests from users. If transparency is a priority, prefer open-source alternatives where the code is publicly available for inspection.