What Is an Infected SIM Card?

By Andrea Stein

An infected SIM card can transfer a virus to a cellular phone.
i Cell phone image by Elzbieta Sekowska from Fotolia.com

Users can switch between mobile devices via a Subscriber Identity Module (SIM) card. A SIM card can become infected during this process, which can cause problems with the operation of a mobile device.


A SIM card is a removable card used in certain mobile devices, such as Global System for Mobile Communications phones. SIM cards identify users via an International Mobile Security Identity key, which allows subscribers to switch between phones in a network by removing a SIM card from a mobile phone and inserting it in another phone.


A SIM card can become infected via an existing virus from the mobile device to which it is connected. Viruses spread between operating systems via a form of executable code, which can be transferred via a removable medium such as a SIM card. If an infected SIM card is removed from the infected mobile device and plugged into a new mobile device, it can also infect the new mobile device.


Reformatting an infected SIM card may be used to clear the virus. In most instances, however, the infected card must be replaced. Mobile device antivirus software can be installed, which is used to detect and remove viruses found on the device.