The Rise of IoT Botnets in 2026: What Connected Device Owners Need to Know

Secure IoT House

25 Feb 2026 — 8 min read

Your smart refrigerator might be launching cyberattacks right now, and you'd never know it. IoT botnets—armies of compromised connected devices—have evolved from proof-of-concept threats to sophisticated criminal infrastructure responsible for some of the internet's most devastating attacks. In 2026, understanding this threat isn't just for security professionals; it's essential knowledge for anyone with a smart home, connected camera, or internet-enabled appliance.

The Current Botnet Landscape: 2026 Reality Check

The numbers are staggering. Security researchers estimate that over 18 billion IoT devices are currently connected to the internet, and approximately 2.4 billion of them exhibit exploitable vulnerabilities. Recent botnet campaigns have recruited networks exceeding 4 million compromised devices—each one someone's doorbell, baby monitor, or router silently participating in criminal activity.

Unlike the Mirai botnet that shocked the world in 2016, modern IoT botnets are more sophisticated, resilient, and profitable. They're operated by organized crime groups, nation-state actors, and ransomware cartels. They're not just launching DDoS attacks anymore—they're stealing data, mining cryptocurrency, distributing malware, and enabling fraud at scale.

What Exactly Is an IoT Botnet?

Think of a botnet as a zombie army, but instead of bodies, it's made of smart devices. Here's how it works:

The Infection Process:

Scanning: Attackers use automated tools to scan billions of IP addresses, looking for vulnerable IoT devices
Exploitation: They exploit weak passwords, unpatched vulnerabilities, or backdoors to gain access
Infection: Malware is installed that gives attackers remote control
Command and Control: The infected device connects to a C2 (command and control) server
Weaponization: Your device now follows commands—launching attacks, proxying traffic, or stealing data

What makes IoT devices perfect botnet soldiers:

They're always on and connected
Most users never monitor them for suspicious behavior
They have terrible default security (weak passwords, no updates)
Manufacturers often abandon security updates after 1-2 years
Users rarely change default credentials
They have sufficient bandwidth and processing power for attacks

The Evolution: From Mirai to Modern Threats

2016: The Mirai Wake-Up Call

Mirai changed everything. Using just 60 default username/password combinations, it recruited over 600,000 devices and launched a 1.2 Tbps DDoS attack that knocked major websites offline for hours. The source code was released publicly, spawning countless variants.

Mirai's Legacy:

Proved IoT devices could generate massive attack power
Showed how trivial exploitation could be (default credentials)
Created a blueprint copied by hundreds of botnet operators
Demonstrated that manufacturers weren't taking security seriously

2020-2023: Botnet Diversification

Botnets evolved beyond simple DDoS:

Mozi: Hijacked routers and DVRs using DHT (distributed hash table) for peer-to-peer C2, making it nearly impossible to take down
Emotet: Added IoT devices to its spam and malware distribution empire
Pink: Targeted SOHO routers specifically, creating a persistent proxy network for fraud
Dark Nexus: Introduced botnet-as-a-service rental models

2024-2026: The Professionalization Era

Today's IoT botnets operate like legitimate businesses:

Modern Capabilities:

Multi-stage infection with polymorphic code
Exploitation of zero-day vulnerabilities
Use of legitimate cloud services for C2 (hiding in plain sight)
Rental models (botnet-as-a-service) starting at $50/hour
Specialization (some focus on cameras, others on routers, some on specific brands)
Data exfiltration and credential theft beyond simple DDoS
Cryptomining operations that throttle to avoid detection

Current Major Players in 2026:

Tsunami Redux: A resurgent variant targeting enterprise IoT (industrial sensors, building management)
Nexus Collective: Specializes in high-bandwidth devices for DDoS-for-hire
ShadowProxy: Builds proxy networks from compromised home routers for fraud and anonymization
DataHarvester: Focuses on cameras and voice assistants for espionage and data theft

How Your Device Gets Compromised

Attack Vector #1: Default Credentials (Still #1 After All These Years)

Despite a decade of warnings, default passwords remain the primary infection method.

Common Default Credentials Attackers Try:

admin/admin
admin/password
root/root
admin/12345
support/support
Administrator/(blank)

Attackers maintain databases of default credentials for thousands of device models. Automated scanners try these combinations across millions of IP addresses daily. If your device still uses factory settings, it's likely already been scanned.

Attack Vector #2: Unpatched Vulnerabilities

IoT devices run software with bugs, just like computers. But unlike your laptop that updates weekly, most IoT devices:

Never receive security patches
Require manual firmware updates users don't perform
Are abandoned by manufacturers 1-2 years after release
Have undisclosed vulnerabilities discovered after launch

Recent examples:

CVE-2025-XXXX: Zyxel router command injection affecting 200,000 devices
CVE-2024-XXXX: Hikvision camera authentication bypass (millions affected)
CVE-2024-XXXX: TP-Link router RCE (remote code execution)

Attack Vector #3: Supply Chain Compromise

Sometimes devices ship pre-infected:

Malicious firmware from compromised manufacturers
Backdoors intentionally placed by vendors
Third-party component vulnerabilities
Counterfeit devices with malware pre-installed

The scariest part? You can do everything right and still get infected if the device was compromised before you bought it.

Attack Vector #4: Network-Based Propagation

Once one device is infected, it can spread to others:

Exploiting other devices on your local network
Using your WiFi to infect neighbors' devices
Propagating through VPN connections if you remote into your home
Leveraging UPnP to open firewall holes for external access

Signs Your Device Might Be Part of a Botnet

Performance Red Flags:

Unexplained slowness or lag
Increased data usage (check router logs)
Device runs hot or consumes more power
Internet connection slower than usual
Device reboots randomly

Network Indicators:

Unknown outbound connections in router logs
Traffic to suspicious IP addresses (especially foreign countries you don't interact with)
High volumes of DNS queries
Connection attempts on unusual ports (23 Telnet, 48101, 5358, etc.)
Traffic when you're not actively using the device

Behavioral Changes:

Settings changed without your input
New user accounts you didn't create
Disabled security features
Firmware version downgrades
Password changes you didn't make

External Indicators:

Your IP address appears on spam blacklists
ISP contacts you about unusual traffic
You receive abuse complaints
Your device appears in Shodan searches as publicly exposed

The Real-World Impact of Botnets

On Victims (That's You)

Direct Consequences:

ISP bandwidth throttling or service termination
Legal liability for attacks launched from your IP
Degraded internet performance
Privacy invasion (cameras and microphones hijacked)
Data theft (credentials, personal information)
Increased electricity bills (cryptomining)
Device lifespan reduction (excessive CPU/network usage)

On Attack Targets

Modern botnets have taken down:

Major cloud providers (AWS, Azure outages)
Financial institutions during business hours
Gaming platforms and services
Government websites
Critical infrastructure (reported but not publicly confirmed)
VoIP services and communication platforms

A 2025 study estimated the global economic impact of IoT botnet-enabled cybercrime at $47 billion annually. That's not just DDoS downtime—it includes fraud, data breaches, ransomware distribution, and more.

Protection: A Layered Defense Strategy

Layer 1: Device Hardening (Critical Priority)

Immediate Actions:

Change every default password - Use unique 16+ character passwords per device
Update firmware now - Check manufacturer websites, not just in-app updates
Disable unused features - Telnet, SSH, UPnP, remote access
Disable WPS on routers - It's a persistent vulnerability
Enable automatic updates - If the manufacturer is trustworthy and offers it

Advanced Hardening:

Disable internet access for devices that don't need it (smart light bulbs, for example)
Use local control (Home Assistant, Hubitat) instead of cloud-based
Enable 2FA on device manufacturer accounts
Configure device firewalls if available

Layer 2: Network Segmentation

Why It Matters: If your IoT network is isolated from your primary network, a compromised smart bulb can't access your laptop with tax documents or work files.

Implementation Options:

VLAN segmentation (best): Separate virtual networks at the router level
Multiple SSIDs (good): Guest network for IoT devices
Separate physical router (acceptable): Second cheap router just for IoT
IoT firewall rules: Block IoT devices from accessing non-essential internet resources

Network Architecture Example:

Internet → Router
    ├─ Primary Network (computers, phones, trusted devices)
    ├─ IoT Network (smart home devices - restricted outbound)
    └─ Guest Network (visitors - no local access)

Layer 3: Network Monitoring and Detection

You need visibility into what your devices are doing.

Monitoring Tools:

Router traffic logs: Enable and review monthly
Network scanning: Fing, Angry IP Scanner, nmap for device discovery
Traffic analysis: ntopng, Wireshark for deep packet inspection
Commercial solutions: Firewalla, Cujo, Dojo for automated threat detection

What to Monitor:

Data volume per device (sudden spikes = red flag)
Connection destinations (unknown IPs, especially foreign)
Connection patterns (activity when you're asleep)
New devices appearing on network
Port scan attempts

Set Up Alerts For:

Unusual bandwidth consumption
Connections to known malicious IPs (threat intelligence feeds)
Devices communicating on Telnet (port 23) or other legacy ports
Failed authentication attempts
New devices joining network

Layer 4: Perimeter Defense

Router-Level Protection:

Change router admin password - Router compromise = full network compromise
Disable remote management - Unless you absolutely need external access
Enable router firewall - Block inbound connections by default
Disable UPnP - Prevents devices from opening ports automatically
Use secure DNS - Cloudflare 1.1.1.1, Quad9, or Pi-hole with filtering
Enable DNSSEC - Prevents DNS spoofing

Advanced Perimeter:

Intrusion detection/prevention (Snort, Suricata, or commercial IDS/IPS)
Geo-blocking (block countries you never interact with)
Rate limiting on outbound connections
Deep packet inspection where feasible

Layer 5: Device Lifecycle Management

Purchase Phase:

Research manufacturer security track record
Check average support duration (aim for 5+ years)
Verify devices receive regular updates
Look for security certifications (if any exist)
Avoid cheap unknown brands

Operational Phase:

Quarterly firmware check and update
Annual security audit of all devices
Monitor manufacturer security bulletins
Review device necessity (do you still need it?)

End-of-Life Phase:

Replace devices that no longer receive updates
Properly wipe/factory reset before disposal
Consider offline alternatives for replaced devices

What To Do If You're Already Compromised

Immediate Response (First Hour):

Isolate the device: Disconnect from network (unplug ethernet, disable WiFi)
Document everything: Screenshot logs, write down observations
Don't delete yet: Preserve evidence if you need to report it
Check other devices: Infection may have spread

Remediation Steps:

Factory reset the compromised device - Consult manual for proper procedure
Update firmware before reconnecting - Download from manufacturer site (not device)
Change all passwords - Device, manufacturer account, router
Scan network for other infections - Use security scanner
Review router logs - Identify other potentially compromised devices
Change router password - If device had access to network settings

Post-Incident:

Monitor device closely for 30 days
Consider replacing if behavior remains suspicious
Report incident to manufacturer
Report to ISP if they contacted you
Consider reporting to CISA (US) or equivalent agency

The Future of IoT Botnets: What's Coming

Emerging Threats:

AI-powered botnets: Adaptive attacks that learn and evade detection
5G device targeting: Higher bandwidth = more powerful attacks
Cross-platform infections: Botnets that jump between IoT, mobile, and desktop
Supply chain attacks: More pre-infected devices from compromised manufacturers
Smart city infrastructure: Traffic systems, utilities, public WiFi becoming targets
Medical IoT: Healthcare devices as botnet soldiers (terrifying implications)

Industry Response (Slowly Improving):

Matter/Thread protocols with security built-in
Government regulations (EU Cyber Resilience Act, US IoT labeling)
Manufacturer liability for insecure devices
ISP-level botnet detection and quarantine
Security by design movements

The Bottom Line: Your Responsibility

Here's the uncomfortable truth: you're responsible for securing your devices. Manufacturers often ship insecure products, and regulators are slow to enforce standards. Your compromised camera doesn't just affect you—it becomes part of an attack that harms others.

The Three-Step Minimum:

Change every default password (takes 30 minutes)
Update all firmware (takes 1 hour)
Enable network segmentation (takes 2 hours)

These three steps alone will prevent 90% of IoT botnet infections.

Think of it this way: Every unsecured IoT device is like leaving your car running with the keys in it. Sure, you might be the victim if it's stolen—but that car might be used in a crime that hurts someone else. Digital citizenship means securing your devices.

The rise of IoT botnets in 2026 isn't a distant threat or theoretical risk. It's happening right now, at massive scale, and statistically, several of your devices have already been scanned by attackers. The question isn't "Will my devices be targeted?" but "When will they be targeted, and will I be ready?"

Start securing your IoT ecosystem today. Your network—and the internet—will be safer for it.