Owners of Xiaomi, Redmi and POCO smartphones often face intrusive notifications that the system flags as unwanted. The mechanism for recognizing such messages is deeply integrated into the MIUI shell and the new HyperOS, working on several levels, from analyzing network packets to verifying digital signatures of applications. Understanding exactly how security algorithms classify traffic allows users to fine-tune the device to their needs.
It doesn't just rely on blacklists, it uses real-time heuristic analysis of application behavior, and if it starts sending queries or showing content on top of other windows, the protection module responds instantly, and it's a complex ecosystem where local rules intertwine with cloud-based databases of antivirus vendors.
It is important to distinguish between a system spam filter and an ad blocker in a browser or system applications. Although they use similar patterns, their application points are different.
The MIUI Security Architecture
The central element of protection is the Security app, which works as a system service with high privileges, not only scans the APK files that are installed, but also analyzes the behavior of processes that are already running, and the key component here is the Avast or Antiy engine (depending on the firmware region), which receives regular updates of virus signatures and spam.
The algorithm detects spam by tracking the frequency of pop-ups and the nature of their content. If an application tries to run activity in the background without user interaction, it is flagged as suspicious. The system also checks developers' digital certificates: applications from unknown, low-ranking authors in the GetApps store are subject to more stringent verification.
⚠️ Warning: Disabling system security components may lead to the installation of malware that steals banking data.Do not delete the Security app".
Behavior emulation is used for deep analysis, and before launching suspicious code, the system can isolate it in a sandbox to assess potential harm. If an application tries to access contacts or SMS without the explicit permission of the user, the security mechanism blocks this action and notifies the owner.
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Xiaomi’s security system works in real time, analyzing not only files, but also the behavior of running processes in an isolated environment.
Analysis of SMS and incoming calls
Incoming and calling filtering is based on a combination of local databases and cloud services. When an SMS arrives, the system checks the sender's number against a global spam database. If a number is labeled by multiple users as advertising or fraudulent, the message automatically enters the Spam folder.
The algorithm looks for phishing keywords: "Your account is blocked," "urgently click on a link," "winning." Detecting these patterns in combination with an unknown sender number increases the message's risk rating. The user can train the system by tagging false positives.
- 📱 Automatic lock of numbers from unknown regions when the mode is turned on".
- 🔍 Scanning. URL-address SMS for the presence of known phishing domains.
- 🛡️ Isolation of messages from bank service numbers if they do not correspond to the format of official mailings.
Importantly, an active Internet connection is required to run a cloud database efficiently, and without it, the system relies only on local heuristics, which can reduce the effectiveness of protection against new types of spam. Regular updates of signature databases occur in the background through the Security app.
Blocking Advertising in System Applications
Many users confuse spam with native ads embedded in Xiaomi system applications, using MSA (MIUI System Ads) to combat this. Although technically not spam in the classical sense, the system's algorithms allow you to control its display. Disabling ads requires manual intervention in the settings of each component.
The system identifies ad modules by their behavior: downloading content from ad servers and rendering banners in the interface. Users can limit this process by banning applications from using data in the background, which prevents new ad units from being loaded when the application is folded.
To be fully controlled, you have to go through the setup chain, first of all, you disable ad personalization, which breaks the link between your OAID ID and your ad profiles, and then manually remove recommendations in folders and on the desktop.
☑️ Disabling advertising in MIUI
Protection during application installation (Install Monitor)
When attempting installation APK-A third-party file is run by a rigorous verification module, which analyzes the permissions requested and compares them to the functionality of the application. SMS, This is the first line of defense against potential spam software.
During the installation, the integrity of the package and the presence of embedded malicious code are checked. If the application is signed with an unknown certificate or its hash amount matches the database of known threats, the installation will be blocked or restricted.
| Level of risk | Operation of the system | User capabilities |
|---|---|---|
| Safe. | Automatic installation | Standard process |
| Suspiciously. | Warning and timer | Wait 10 seconds for confirmation |
| Dangerous. | Locking the installation | Requires manual removal of the lock in the settings |
| Virus detected | Total ban and removal | Cannot be installed without disabling the protection |
It is worth considering that aggressive settings can block legitimate but rarely used applications, in such cases, you need to temporarily exclude the file from the check or add to the whitelist, but this should only be done if you are absolutely sure about the source of the file.
Network Screen and Traffic Control
The built-in network screen monitors incoming and outgoing connections, detects spam activity by abnormal network traffic, and if an application starts sending data to unknown servers or engages in a DDoS attack (a sign of a botnet), the connection is cut off, a critical level of protection against Trojans and spyware.
The user can customize the rules for each application individually, for example, you can prevent the browser from accessing the network in the background, which will prevent heavy advertising and trackers from loading until you use the device, and the function of blocking incoming calls for hidden numbers is also available.
⚠️ Attention: Blocking system processes in the network screen can lead to incorrect notifications (Push) from messengers and mail.
For advanced users, detailed logging is available; you can see in the logs which domains the application is trying to connect to; often there are ads that are not formally viruses, but consume traffic and battery; blocking such domains through a hosts file or Private DNS is an effective method of combating spam at the network level.
How to use Private DNS to block ads?
The Role of Cloud Databases and Updates
The effectiveness of spam detection depends on the relevance of cloud databases. Xiaomi cooperates with leading antivirus laboratories, which update lists of malicious URLs and phone numbers daily. Without regular updates of the virus database, local protection becomes less effective against new threats.
Updates are automatic, but the user can initiate manual verification through the Security app. It is important that the date and time on the device are set correctly, otherwise SSL-Certificates may not be validated and database updates may not load, which is a common reason why security stops updating.
New versions of HyperOS introduce more intelligent on-device AI, which reduces the amount of information transferred to the cloud. Machine learning algorithms analyze spam patterns locally, which increases the speed of response and preserves the confidentiality of user data.
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For maximum protection, regularly update not only the system, but also the Security app through the GetApps store, even if the system says that there are no updates.