🤖 Overview

check1.exe is a legitimate web crawler operated by Check-Host.net, a public website monitoring service that provides uptime and performance reports. It periodically fetches target URLs to verify that they respond correctly, serving as a tool for webmasters and businesses to ensure their sites remain accessible.

🌐 Technical Behavior

The crawler issues simple HTTP or HTTPS GET requests to the monitored URL, typically once every 5 to 60 minutes depending on the user’s subscription plan. It does not follow links, parse JavaScript, or download large assets; it only retrieves the initial document to check response codes and latency. The User-Agent string check1.exe is sent without a version number, and the bot originates from a dynamic set of IP addresses listed on Check-Host.net’s official IP range documentation. These addresses are primarily from data centers in the United States and Europe. The bot respects standard HTTP caching headers and performs requests with typical headers like Accept and User-Agent, but it omits browser-specific headers such as Accept-Language or Sec-Fetch-*.

📋 robots.txt Compliance

According to Check-Host.net’s official FAQ and robots.txt handling policy, check1.exe fully honors the robots exclusion standard. It reads the robots.txt file at the root of each domain and will not crawl any path marked with Disallow. Additionally, the service allows webmasters to define a custom crawl delay via the Crawl-Delay directive to reduce request frequency.

🔍 Detection Indicators

The primary identifier is the exact User-Agent string check1.exe (case-sensitive). The bot also sends a From header containing the email address of the Check-Host.net account that owns the monitor. No other distinguishing headers are added, but the lack of Referer and Accept-Encoding can help differentiate it from normal browsers. Reverse DNS lookups on connecting IPs often resolve to hostnames under the check-host.net domain.

📊 Data Usage

Collected data consists solely of HTTP response status codes, response times, and content size. Check-Host.net aggregates these metrics to produce uptime percentages and latency graphs for each monitored site. No personal, sensitive, or user-submitted content is stored or transmitted to third parties; the data is used exclusively for the monitoring dashboard and alerts configured by the account holder.

⚙️ Rate Limiting Policy

Because check1.exe can send requests as frequently as every 5 minutes per monitored URL, it is standard practice to rate-limit it to avoid server overload. Check-Host.net itself advises that threshold-based rate limiting (e.g., 60 requests per minute per IP) is appropriate, and that blocking the bot outright is unnecessary as long as the rate does not exceed normal human browsing levels.

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the bots listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.