According to security specialists, these silent calls function as a form of automated reconnaissance. Fraud operations run large-scale calling systems that dial thousands of numbers to determine which ones belong to real people. When someone answers, the system confirms that the number is active and marks it as a potential target for future scams.
Keeper Security Chief Information Security Officer Shane Barney explained that such calls are rarely accidental. Instead, they help attackers filter out inactive numbers before investing more time and resources into scams. Verified contact information has value in modern cybercrime networks, where data about reachable individuals can be bought, sold, and reused across different fraud campaigns.
Once a phone number is confirmed as active, it may be used in several ways. In some cases, scammers follow up with phishing calls or messages designed to trick victims into revealing personal or financial information. In more advanced attacks, a verified phone number could be combined with leaked email addresses from data breaches or used in schemes such as SIM-swap fraud, where attackers attempt to gain control of a victim’s mobile account.
Another variation occurs when callers respond only after a brief pause. This delay is typically caused by predictive dialing systems that automatically place large volumes of calls. These systems detect when a human answers and then route the call to a live operator. The short silence represents the time it takes for the system to transfer the connection.
Some people also worry that speaking during these calls could allow scammers to clone their voice using artificial intelligence. While voice cloning technology exists, experts say creating a convincing replica generally requires longer and clearer audio samples than a brief greeting.
However, voice cloning could still become part of larger scams if criminals already possess other personal details about a victim.
Security professionals recommend simple precautions when receiving suspicious calls. If an unknown number produces silence, hanging up immediately is usually the safest option.
Another tactic is answering without speaking, which prevents automated systems from detecting a human voice.
Spam-filtering tools can also help reduce nuisance calls. Applications such as Truecaller, RoboKiller, and Hiya identify numbers previously reported as spam. However, experts caution that no filtering system is perfect because scammers frequently change phone numbers.
Ultimately, while call-blocking tools can reduce the volume of unwanted calls, maintaining strong account security and being cautious with unknown callers remain the most effective ways to avoid phone-based scams.
