Public IP addresses of home users and small businesses are increasingly abused as part of botnets and residential proxy networks, often without the owner’s knowledge. To help detect this kind of hidden misuse, GreyNoise has launched a free online service called GreyNoise IP Check, which evaluates whether a given public IP has been observed in mass scanning, malicious automation, or proxy-like behavior on the internet.
Growing abuse of home IP addresses and residential proxy networks
The market for residential proxies has expanded rapidly in recent years. In these networks, the internet connection of ordinary users is turned into an exit node that forwards someone else’s traffic. For attackers and shady operators, this is attractive because their activity appears to originate from legitimate home or small-office IP addresses rather than from known data centers or VPN endpoints.
Some users knowingly install special software or browser extensions and agree to share their bandwidth in exchange for small payments, discounts, or in-app rewards. The more serious problem arises when enrollment into these networks happens without informed consent—for example via malicious mobile apps, trojanized browser extensions, pirated software, or compromised IoT devices such as cameras, smart TVs, and home routers.
In such scenarios, the owner may have no idea that their IP address is being used for botnet attacks, credential stuffing, mass scanning, or other forms of abuse. Industry reports from multiple security vendors consistently show that poorly secured IoT and home networks are among the most common entry points for large botnets and proxy infrastructures.
Free IP reputation check for botnets and suspicious activity
GreyNoise IP Check offers a simple first step to understand how an external observer sees your public IP address. The user enters an IP, and the service returns a high-level verdict based on GreyNoise’s telemetry of internet-wide scanning and automated activity. This is less intrusive than a full security audit and provides quick context for home users, small businesses, and security teams.
Three GreyNoise IP Check verdicts for IP reputation
The service leverages GreyNoise’s large-scale sensor network, which continuously monitors unsolicited traffic hitting exposed systems on the internet. Based on this data, each IP address receives one of three statuses:
1. Clean – No suspicious or abnormal activity from this IP has been observed in recent weeks. This does not guarantee that the network behind the IP is fully secure, but it indicates that the address has not been seen in typical botnet, scanning, or attack traffic captured by GreyNoise.
2. Malicious / Suspicious – The IP has been observed in active internet scanning, anomalous requests, exploit attempts, or other automated behaviors often linked to compromised hosts or abuse. For such IPs, GreyNoise IP Check displays a 90‑day activity history, giving approximate timing and nature of the suspicious traffic that was seen.
3. Common Business Service – The IP belongs to a legitimate infrastructure provider such as a VPN service, large enterprise network, or cloud data center. For these ranges, high volumes of automated or scanning traffic may be normal, and the verdict does not necessarily imply compromise.
GreyNoise IP Check JSON API for security automation
For more advanced users and security operations teams, GreyNoise exposes an unauthenticated JSON API for IP checks, with no strict request-rate limitations. This allows organizations to integrate IP reputation data directly into existing monitoring and incident response workflows.
Typical use cases include:
— Automated bulk IP reputation checks from web server, VPN, email, or firewall logs to quickly identify likely scanners and botnet nodes.
— Enriching alerts in SIEM and SOAR platforms with context from GreyNoise to prioritize true threats over background internet “noise”.
— Integrating with custom scripts and monitoring tools to flag when critical systems are contacted by IPs known for scanning, brute-force attempts, or other automated attacks.
Actions to take if your IP is marked as Malicious / Suspicious
If GreyNoise IP Check reports your address as Malicious / Suspicious, it is a strong signal that you should investigate potential compromise within your local network. A reasonable baseline response plan includes the following steps:
— Run full antivirus and EDR (Endpoint Detection and Response) scans on all endpoints connected to the network: desktops, laptops, smartphones, and servers.
— Pay particular attention to routers, smart TVs, and other IoT devices, which are frequently left unpatched and may be taken over via firmware vulnerabilities or weak default passwords.
— Update the firmware of routers, IP cameras, media boxes, and other connected devices to the latest vendor-supported versions.
— Change administrator passwords on all network equipment and disable remote administration features that are not strictly necessary.
— Where possible, implement basic network segmentation, for example by placing IoT devices on a separate guest Wi‑Fi network to limit the blast radius of any single compromise.
For organizations, it is also advisable to correlate the timeframe of the IP’s suspicious activity—visible in the GreyNoise history—with internal logs from VPN concentrators, proxy servers, and remote access systems. This can help identify which user accounts or hosts may have generated the flagged traffic and whether additional containment or forensics is required.
As modern botnets and residential proxy networks increasingly exploit weakly protected home and small office environments, tools like GreyNoise IP Check become a practical part of everyday cyber hygiene. Regularly checking your public IP reputation, keeping firmware and software up to date, avoiding untrusted applications, and tightening control over network devices substantially reduce the risk that your internet connection will be quietly turned into an asset for cybercriminals. Incorporating such checks into routine security practices—alongside backups, patching, and strong authentication—helps ensure that your IP address remains part of the solution, not part of someone else’s attack infrastructure.
