A botnet is a network of internet-connected devices infected with malware that allows attackers to control them remotely. The infected devices — called bots or zombies — operate normally for their owners while silently participating in attacker-directed activities.
Botnets can include thousands to millions of devices: home computers, smartphones, smart home devices, servers, and IoT gadgets.
How Devices Become Part of Botnets
Malware infection: Clicking malicious links, opening infected attachments, or downloading software from untrusted sources installs bot malware.
Unpatched vulnerabilities: Outdated software with known security flaws is automatically exploited by botnet recruitment tools that continuously scan the internet.
Weak credentials: Devices with default or weak passwords — particularly IoT devices — are compromised by credential stuffing attacks.
Drive-by downloads: Visiting compromised websites automatically installs bot malware through browser vulnerabilities.
What Botnets Are Used For
Distributed Denial of Service (DDoS) attacks: Thousands of bots simultaneously send traffic to a target server, overwhelming and taking it offline.
Spam distribution: Millions of spam emails are sent through compromised devices, making source identification difficult.
Credential stuffing: Bot networks test breached credential lists against target websites at scale.
Cryptocurrency mining: Bot devices mine cryptocurrency for the attacker.
Click fraud: Bots click on advertisements to generate fraudulent advertising revenue.
Data theft: Some bots steal files, credentials, and personal information from infected devices.
Ransomware distribution: Botnets distribute ransomware payloads to new victims.
Proxy services: Infected devices provide IP addresses for other criminal activities.
How to Check If Your Device Is Infected
Unusual network activity: Monitor your router's traffic logs or use network monitoring software. Botnets communicate with command and control servers — unexpected traffic to unfamiliar IP addresses is a warning sign.
High resource usage: CPU, memory, and network usage that is unexplainably high, particularly when you are not actively using the device.
Antivirus and anti-malware scan: Run a full system scan with updated security software. Modern antivirus products detect most known botnet malware.
Security community resources: Check botnet membership lookups like those provided by national CERTs (Computer Emergency Response Teams) and security organizations.
How to Remove Bot Malware
Run antivirus and anti-malware scans and remove detected threats. Check startup programs and remove unfamiliar entries. For severe infections, a clean OS reinstall is the most reliable solution. After cleaning, change all passwords from a trusted clean device.
Prevention
Keep all software updated — OS and applications. Use a password manager with strong unique passwords. Do not click on unexpected links or attachments. Only download software from official sources. Secure IoT devices with changed default credentials and network segmentation.
Botnets and Email
Botnets are responsible for the majority of global spam email. When your device is in a botnet, spam may be sent from your IP address — potentially affecting your email sender reputation and making your IP appear on spam blacklists.
Using Temp90 for registrations does not directly affect botnet risk, but maintaining device security (which prevents botnet infection) protects both your device and your email sending reputation.
Frequently Asked Questions
How can I tell if my IP is on a spam blacklist due to botnet activity?
Check your IP at mxtoolbox.com/blacklists.aspx. If your IP appears on spam blacklists, your ISP may need to be contacted, and your device should be cleaned of malware.
If my device is in a botnet, does the attacker have access to my files?
Depends on the botnet type. Some botnets are purely for DDoS or spam purposes. Others include data theft capabilities. Assume the worst and treat any botnet infection as a complete device compromise.
Who controls botnets?
Botnets are typically controlled by organized criminal groups, nation-state actors, or individuals selling botnet services to others. Law enforcement periodically disrupts and dismantles major botnets.
Conclusion
Botnets silently co-opt your device's resources for criminal purposes without your knowledge. Preventing infection through software updates, safe downloading practices, and device security is the primary defense. Regular antivirus scans provide detection capability. And securing IoT devices — often the weakest link in home networks — prevents your smart devices from becoming botnet entry points.