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Why do bots and fake data submit web forms?

Matthew Whittaker profile picture
Matthew Whittaker
Co-founder & CTO, Suped
Published 11 May 2025
Updated 30 Sep 2025
7 min read
The internet is a vast landscape, and while much of its traffic comes from legitimate users, a significant portion originates from automated programs, commonly known as bots. These bots are constantly scanning the web, interacting with websites in various ways, including submitting web forms. It's a pervasive issue that can lead to skewed data, wasted resources, and even security risks for businesses of all sizes.
For many, the question arises: why would bots bother filling out forms if there's no immediate gain? The reality is, bot motivations are diverse and often hidden, ranging from simple reconnaissance to sophisticated malicious attacks. Understanding these underlying reasons is the first step in effectively combating fake data submissions and protecting your online assets.
This challenge extends beyond simple spam. Bots can mimic human behavior, making them difficult to detect without robust protection mechanisms. The consequences of unchecked bot activity can severely impact marketing efforts, lead generation, and overall data integrity. Learning why they do what they do helps us build better defenses.

Understanding bot motivations

Bots submit web forms for a multitude of reasons, many of which are nefarious. One primary motivation is to simply flood forms with irrelevant or junk data, often as a form of spam or to promote illicit products and services. These submissions can overwhelm systems, clog inboxes, and consume valuable processing power. Beyond direct spam, bots are also used for data harvesting, collecting email addresses or other personal information from forms that might be later used for targeted phishing campaigns or identity theft.
Another significant reason is vulnerability scanning and exploitation. Bots will blindly try to submit forms to identify weaknesses in your website's security. This could involve attempting SQL injections, cross-site scripting (XSS), or simply overloading the server to expose error messages that reveal system information. Such attacks are often precursors to larger, more damaging cyber incidents. Attackers may also leverage email flooding to hide account takeover notifications, burying critical alerts in a deluge of junk emails.
Bots are also deployed for economic reasons, particularly in the realm of lead generation fraud. If a business pays affiliates or advertisers based on form submissions or sign-ups, malicious actors can use bots to generate fake leads, inflating their numbers and siphoning ad spend. This directly impacts marketing budgets and skews performance metrics. You can learn more about this by reading what are the purposes of bots signing up.

Bot type

Primary objective

Impact on forms

Spam bots
Distribute unsolicited content, links, or promotions
Fill contact forms, comment sections with junk data
Scraper bots
Collect data like email addresses, product prices
Submit forms to access gated content or specific data sets
Vulnerability bots
Identify security flaws in web applications
Attempt malicious inputs (SQLi, XSS) through form fields
Fraud bots
Generate fake leads, inflate metrics, or create fake accounts

The impact of fake form submissions

The repercussions of fake form submissions can be far-reaching, impacting various aspects of your business. One of the most immediate effects is skewed data and analytics. When your forms are filled with bot-generated garbage, your lead conversion rates, user engagement metrics, and campaign performance data become unreliable. This makes it impossible to make informed marketing and business decisions, leading to misallocated resources and missed opportunities.
Beyond data integrity, fake submissions can waste significant operational resources. Sales teams might waste time chasing fake leads, customer service departments could be overwhelmed by spurious inquiries, and email marketing platforms might charge for sending emails to invalid or bot-generated addresses. This can also lead to increased spam rates for your email marketing efforts, damaging your sender reputation.
A damaged sender reputation can have severe long-term consequences, including emails landing in spam folders or even being outright rejected. This not only affects your ability to communicate with legitimate customers but can also trigger blocklisting (or blacklisting) of your IP address or domain. Utilizing DMARC monitoring and blocklist monitoring can help you stay ahead of these issues by giving you visibility into your email ecosystem.

The silent impact of bot submissions

Bot submissions are not always immediately obvious. They silently inflate your lead counts, distort conversion metrics, and quietly erode trust in your data. This subtle corruption can lead to flawed strategic decisions and misdirected marketing efforts, costing businesses valuable time and money before the problem is even recognized. Constant vigilance is key.

Distinguishing bots from human errors

It's crucial to understand that not all invalid form submissions originate from malicious bots. Sometimes, human error can also lead to fake data. For instance, users might intentionally enter incorrect email addresses to access gated content or receive a quote without being added to a marketing list. This is a common issue in industries like insurance, where customers may provide fake information to avoid follow-up emails from multiple providers.
These deliberate false entries by humans can sometimes appear similar to bot activity, making detection more complex. The difference lies in the intent: one is driven by a human desire to circumvent unwanted communication, while the other is an automated program with a potentially malicious agenda. Both, however, result in dirty data and operational headaches, and both can lead to spam traps if these email addresses are sent to.
Distinguishing between these two types of submissions often requires analyzing behavior patterns beyond simple form entries. Sophisticated bots can mimic human interaction, filling out multi-page forms and even solving basic CAPTCHAs, especially when human solvers are employed through services like Amazon Mechanical Turk. This makes a multi-layered detection strategy essential.

Bot submissions

  1. Automated: Performed by scripts or software programs.
  2. Malicious intent: Spam, fraud, data harvesting, vulnerability exploitation.
  3. Scalable: Can generate large volumes of submissions quickly.

Human errors or deliberate fake data

  1. Manual: Entered by actual users, sometimes paid via micro-task platforms.
  2. Circumvent intent: Avoid unwanted marketing or follow-up communications.
  3. Varied volume: Can be individual instances or aggregated through incentive programs.

Strategies for mitigating bot interference

Protecting your web forms from bots and fake data requires a multi-faceted approach. Implementing CAPTCHA or reCAPTCHA is a common first line of defense, though advanced bots can sometimes bypass these. Another effective technique is using honeypot fields—hidden fields that only bots will fill out, flagging the submission as spam without impacting legitimate users. Learn more about how to protect email list signup forms.
Beyond technical solutions, regular monitoring of your form submissions for unusual patterns, such as a sudden surge in submissions from specific IP ranges or with generic email domains, is vital. For email list protection, consider implementing a double opt-in process for email subscriptions. This ensures that only legitimate users who confirm their email address are added to your list, significantly reducing the impact of bot-generated email addresses.
It's also important to scrutinize any third-party lead generation partners. If you're compensating vendors on a per-signup basis, there's an inherent incentive for them to feed you fake data. Regularly audit their traffic sources and the quality of leads. Ultimately, a combination of user-friendly bot detection methods and vigilant monitoring is your best defense. Explore reliable methods to identify and prevent bots.
Example of a honeypot field in HTMLhtml
<label for="website">Website (leave blank)</label> <input type="text" id="website" name="website" autocomplete="off" tabindex="-1">

Views from the trenches

Best practices
Implement multi-layered bot detection, combining CAPTCHAs, honeypots, and behavioral analysis.
Regularly monitor form submission data for anomalies, such as suspicious IP addresses or unusual patterns.
Utilize double opt-in for email sign-ups to verify legitimacy and reduce fake entries effectively.
Carefully review compensation models for lead generation partners to avoid incentivizing fake data.
Common pitfalls
Assuming all invalid submissions are from bots; some are legitimate users avoiding marketing emails.
Underestimating the sophistication of modern bots that can mimic human behavior.
Failing to trace submitting IP addresses, which can reveal bot networks or fraudulent sources.
Ignoring the impact of email flooding as a tactic to hide critical security notifications.
Expert tips
Always inspect the IP address of form submissions to identify patterns of automated or suspicious activity.
Evaluate your lead generation contracts, particularly any 'per signup' payment structures that could invite fraud.
Consider a human-behavior analysis layer in addition to technical bot defenses for advanced detection.
Implement email authentication protocols like DMARC to prevent abuse of your domain for spam originating from fake submissions.
Marketer view
Marketer from Email Geeks says attackers may hijack legitimate deliverability to flood inboxes, burying important notifications during account compromises.
2019-08-02 - Email Geeks
Marketer view
Marketer from Email Geeks says many account takeovers use email flooding to hide system notifications that warn the true owner.
2019-08-02 - Email Geeks

Conclusion

The persistent problem of bots and fake data submitting web forms is a multifaceted challenge that requires vigilance and a layered defense strategy. By understanding the diverse motivations behind these automated attacks and the subtle ways humans might also contribute to false data, businesses can implement more effective protective measures. Continuous monitoring, robust technical defenses, and careful scrutiny of lead sources are all essential components in maintaining data integrity and securing your online presence in an increasingly automated world. Suped provides comprehensive DMARC monitoring to help protect your email domain from abuse stemming from these activities.

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Real-time DMARC report monitoring and analysis
Automated alerts for authentication failures
Clear recommendations to improve email deliverability
Protection against phishing and domain spoofing