How to set up security for a linked group

When you link a discussion group to your Telegram channel, you create a direct bridge between your content and your audience — but that bridge needs protection. Properly configuring security for a linked group prevents spam, bot attacks, content leaks, and toxic behavior that can damage your channel's reputation and drive away subscribers.

Understanding Linked Groups and Their Risks

A linked group (also called a discussion group) is a Telegram group chat connected to your channel where subscribers can comment on posts and interact with each other. When you enable comments on your channel, Telegram automatically creates or connects a group where each post's comment thread lives.

This setup introduces several security risks that don't exist for standalone channels:

Spam bots can join the group and flood comment sections
Scammers may impersonate admins or post phishing links
Trolls can harass your community and derail discussions
Competitors might promote rival channels in your comments
Sensitive content shared in the group could reflect poorly on your channel

Because the linked group carries your channel's name and brand, any security failure there directly affects how your audience perceives your channel.

Step 1: Configure Basic Group Settings

Open your linked group by tapping the group name at the top of any comment section, then go to Edit → Group Type.

Set the Group Type to Private

Keep your linked group private rather than public. A private linked group still allows channel subscribers to comment on posts, but it prevents the group from appearing in Telegram search results where spam bots typically find targets.

Go to Group Settings → Group Type → select Private Group
This does not prevent commenting — channel subscribers can still access discussions through the comment button on each post

Restrict Who Can Join

Under Group Settings → Invite Links:

Disable the ability for regular members to create invite links
If you need an invite link, set it to expire after a specific time or number of uses
Revoke any old invite links that may have been shared publicly

Step 2: Set Up Admin Permissions

Proper admin structure is critical. Too many admins with full permissions creates chaos; too few means spam goes unchecked for hours.

Create an Admin Hierarchy

Owner (you): Full permissions, including the ability to add/remove other admins
Senior moderators (1-2 trusted people): Can ban users, delete messages, pin messages, and manage invite links
Junior moderators (2-5 active members): Can only delete messages and restrict users temporarily

Configure Admin Rights Carefully

For each admin, go to Group Settings → Administrators → select the admin → customize their permissions:

Change Group Info: Only for senior moderators and above
Delete Messages: All moderators
Ban Users: Senior moderators and above
Invite Users via Link: Senior moderators only
Pin Messages: Senior moderators and above
Manage Video Chats: Only if you use this feature
Remain Anonymous: Enable for moderators who prefer privacy
Add New Admins: Owner only

Important: Never give Add New Admins permission to anyone except the channel owner. A compromised moderator account with this permission could add malicious admins and take over the group.

Step 3: Configure Anti-Spam and Slow Mode

Enable Telegram's Built-in Anti-Spam

Telegram offers a native anti-spam system for groups with more than 200 members:

Go to Group Settings → Administrators
Find Aggressive Anti-Spam and enable it
This automatically deletes messages flagged as spam and bans repeat offenders

For groups under 200 members, you'll need to rely on bot-based solutions (covered below).

Set Up Slow Mode

Slow mode limits how often each member can send a message, which dramatically reduces spam effectiveness:

Go to Group Settings → Permissions → Slow Mode
Choose an interval: 30 seconds, 1 minute, 5 minutes, 15 minutes, or 1 hour
For most channel discussion groups, 1 minute is a good balance between conversation flow and spam prevention

Restrict Default Member Permissions

Under Group Settings → Permissions, configure what regular members can do:

Permission Recommended Setting Send Messages ✅ Enabled Send Media ✅ Enabled (or ❌ if spam is severe) Send Stickers & GIFs ❌ Disabled Send Polls ❌ Disabled Add Members ❌ Disabled Pin Messages ❌ Disabled Change Group Info ❌ Disabled Manage Topics ❌ Disabled

Disabling Send Stickers & GIFs may seem harsh, but sticker spam is one of the most common disruption tactics in Telegram groups.

Step 4: Deploy an Anti-Spam Bot

For serious protection, add a dedicated anti-spam bot. The most effective options include:

Option A: @GroupHelpBot

Free for basic features
Provides captcha verification for new members
Filters links, forwards, and specific keywords
Logs moderation actions

Option B: @Combot

Advanced analytics and moderation
Custom welcome messages with verification
Reputation system for members
Automatic warnings before bans

Option C: @Rose (Miss Rose)

One of the most popular moderation bots
Supports blocklists, flood control, and media filtering
Custom filters with regex support
Multi-language support

Setting Up a Captcha System

Most anti-spam bots offer captcha verification. This forces new members to prove they're human before they can post:

Add your chosen bot to the group
Grant it admin permissions (delete messages, ban users)
Enable captcha/verification mode
Set a timeout (usually 5 minutes) — users who don't verify get kicked
Choose captcha type: button press, math problem, or custom question

This single step eliminates 90% or more of automated spam.

Step 5: Set Up Content Filtering

Create a Blocked Words List

Configure your moderation bot to automatically delete messages containing:

Cryptocurrency/trading spam keywords (earn money fast, guaranteed profit, DM me for details)
Competitor channel links (use regex patterns like t.me/(?!yourchannel))
Phone numbers or external links (if not relevant to your topic)
Slurs and offensive language specific to your community

Filter Forwarded Messages

Spam accounts often forward promotional messages from other channels. Configure your bot or group settings to:

Restrict forwarding from other channels
Auto-delete messages that contain forwarded content from unknown sources
Flag messages with suspicious link patterns

Step 6: Monitor and Maintain Security

Set Up Logging

Use a bot like @GroupHelpBot or a custom logging bot to track:

Who joins and leaves
Deleted messages and who deleted them
Admin actions (bans, restrictions, permission changes)
Edited messages (spammers sometimes edit innocent messages to add spam after passing moderation)

Regular Security Audits

Perform these checks weekly for active groups (1,000+ members) or monthly for smaller ones:

Review the admin list — remove inactive or compromised admins
Check bot permissions — ensure bots only have necessary permissions
Revoke old invite links
Review banned users list — clean up if it gets too large
Test your captcha system by joining from an alternate account

Tips & Best Practices

Tip 1: Enable Approve New Members in group settings if your channel has fewer than 10,000 subscribers. Manual approval is manageable at this scale and provides maximum protection.
Tip 2: Create a pinned message with clear group rules. Members who understand the boundaries are less likely to cause problems, and moderators have a reference point for enforcement decisions.
Tip 3: Use Telegram's Recent Actions log (available in group admin settings) to review the last 48 hours of admin activity. This helps catch unauthorized changes quickly.
Tip 4: Consider creating your channel's web mirror on platforms like tgchannel.space — having an external web presence means your content remains accessible even if your group faces temporary disruptions.
Tip 5: Set up a private admin chat separate from the linked group where moderators can discuss issues, coordinate responses to raids, and share notes about problematic users.

Common Mistakes

Mistake 1: Giving all admins full permissions
Why it's wrong: If any admin account gets compromised, the attacker has full control. A junior moderator doesn't need the ability to change group info or add other admins.
How to avoid: Follow the principle of least privilege — give each admin only the permissions they need for their role.

Mistake 2: Not setting up a captcha for new members
Why it's wrong: Without verification, automated bots can join and spam your group within seconds. A group with 5,000+ members can receive dozens of bot joins per day.
How to avoid: Deploy an anti-spam bot with captcha verification before your group grows beyond a few hundred members.

Mistake 3: Using a public group type for the linked discussion
Why it's wrong: Public groups appear in search results, making them easy targets for spam networks that scrape Telegram for active groups.
How to avoid: Set the group type to private. Linked group commenting still works — subscribers access discussions through the channel post's comment button.

Mistake 4: Ignoring edited messages
Why it's wrong: A sophisticated spammer posts a normal message, waits for it to pass moderation, then edits it to include spam links or scam content.
How to avoid: Configure your moderation bot to log and flag edited messages, especially those adding links after the initial post.

Mistake 5: Having no moderators in different time zones
Why it's wrong: If all your moderators are asleep at the same time, spammers can operate freely for 6-8 hours. A spam raid at 3 AM can fill your comment sections with hundreds of unwanted messages.
How to avoid: Recruit at least one moderator in a significantly different time zone, or rely heavily on automated bot moderation during off-hours.

Frequently Asked Questions

Does making the linked group private prevent channel subscribers from commenting?
No. Subscribers can still access the discussion by tapping the comment button on any channel post. The private setting only prevents the group from appearing in Telegram's global search.

Can I use multiple anti-spam bots at the same time?
You can, but it's generally not recommended. Multiple bots may conflict — for example, both trying to kick the same user simultaneously or sending duplicate verification prompts. Choose one primary bot and configure it thoroughly.

What should I do during a spam raid?
Immediately enable Restrict New Members in group permissions to prevent new joins. Then activate slow mode at the maximum interval. Clean up spam messages and ban offending accounts. Once the raid subsides, gradually relax restrictions.

How do I handle a compromised admin account?
Remove the compromised admin immediately from the admin list. Review Recent Actions to see what changes they made. Revoke all invite links they may have created. If they added unknown admins, remove those too. Change any shared credentials like bot tokens.

Is it safe to use third-party moderation bots?
Reputable bots like Combot, Rose, and GroupHelpBot are widely used and generally safe. However, only grant them the minimum permissions they need (typically Delete Messages and Ban Users). Avoid obscure bots that request unnecessary permissions like Change Group Info or Add New Admins.