There was a call displaying unknown on screen of my Android mobile and was not saved in call log or call history is it matter to worry

 

There was a call displaying unknown on screen of my Android mobile and was not saved in call log or call history is it matter to worry?

Selecting the appropriate device for the requester based on their SIM card and security settings:
first steps of creating a dummy sim card in a mobile phone:

1. Create an account in trusted sites:

2. Download the pre-shared key of sim card:

3. Create a dummy sim card in a non-smartphone and attach to the dummy sim card to see if the user is able to load the key to unlock the mobile device and load the key to unlock the device in the mobile device:
Selecting the appropriate device for the requester based on their SIM card and security settings.

Please note that, unlike the USB keys and random keys, it is hard to share this keys to mobile devices of security staff from an organization without the organization knowing.

It is a basic requirement for security personnel in large organizations to get all of their devices connected on the network and with the appropriate keys in order to be able to provide a second set of credentials for any of their laptops, mobile devices or desktops for the employees or any visitor who happens to come into the building.

It is common in security organizations to provide security guards with a set of randomly generated passwords for their computers and mobile devices, in order to get access to all of their data or to unlock the devices they provide access to.

1. Select the appropriate device for the requester based on their SIM card and security settings:
- A smart phone using Google Android 2.3.3
- A smart phone using iOS 7.1.4, using the security settings provided by the device manufacturer
- A smart phone using an Apple OS, based on iTunes, in which the device has been configured to enter into the provided security settings and security settings: Enter security settings.

2. Generate and save key, using the provided device:
- Enter the security settings and give access to the internal network and the external networks:
- Enter the security settings and give access to all internal network and external networks
- Enter security settings and give access to the computer system.

- Enter security settings to allow the application to access the computer system and all files and all other applications on the computer system.

- Enter security settings to give access to the outside network and any other non-internet network.

- Enter security settings for any external network and any other internet network.

3. Connect to the requester's computer and see if the key is installed.

Important note: This type of key is not able to unlock a remote computer system, not even in Windows.
Selecting the appropriate device for the requester based on their SIM card and security settings: - Enter the security settings and give access to the internal network and external networks - Enter security settings for any external network and any other non-internet network - Enter security settings for any other external network.