One of the main objectives of WhatsApp is to block the accounts of those users who use its application to send spam. Now, how do you do it without reading the messages and ensuring privacy? The company's software engineer, Matt Jones, has explained that spammers use many techniques , including custom multi-SIM devices and specially coded simulators that disguise themselves as users to run multiple WhatsApp accounts.
The company's goal is to detect these techniques without breaking the encryption and, above all, without reading the content of the messages. To do this, it uses what it calls “user actions”, which include registration metadata and the message delivery rate, allowing you to look at these bits of information without decrypting any messages. If a computer network tries to register wholesale accounts, or a phone number similar to the one that was recently misused, the system throws them away even before these accounts can send a message. The company says that of the two million accounts it bans each month, 20 percent are captured on the registry.
The company's most interesting job in fighting spam occurs when bots try to send messages to people. Look for things like if an account has a "write…" indicator, or if it sends 100 messages in 10 seconds in the five minutes after signing up. Also, if a spam account sends malicious links, WhatsApp marks them as suspicious. In the past year, various Indian political parties used groups to spread propaganda during numerous state elections. To combat it, WhatsApp introduced a feature that allows you to report a group and leave it, so that administrators cannot add you back to the group.
Lastly, WhatsApp kills spammers when other people report them. However, it also ensures that a group of users does not target an individual through mass messages. To do this, it checks if the phone numbers that report a specific user have ever interacted with them. In addition to these measures, WhatsApp recently introduced a global message forwarding limit to a maximum of five accounts, in order to prevent the spread of spam. The company even makes sure its algorithm detects abusers in the modified APKs (Android app installation files) of the chat app.
