Mobile malware is malicious software that targets mobile phones or wireless-enabled Personal digital assistants (PDA), by causing the collapse of the system and loss or leakage of confidential information. As wireless phones and PDA networks have become more and more common and have grown in complexity, it has become increasingly difficult to ensure their safety and security against electronic attacks in the form of viruses or other malware. History The first known virus that affected mobiles, "Timofonica", originated in Spain and was identified by antivirus labs in Russia and Finland in June 2000. "Timofonica" sent SMS messages to GSM-capable mobile phones that read (in Spanish) "Information for you: Telefónica is fooling you." These messages were sent through the Internet SMS gateway of the MoviStar mobile operator. "Timofonica" ran on PCs and did not run on mobile devices so was not a true mobile malware In June 2004, it was discovered that a company called Ojam had engineered an anti-piracy Trojan hack in older versions of its mobile phone game, Mosquito. This sent SMS texts to the company without the user's knowledge. In July 2004, computer hobbyists released a proof-of-concept virus Cabir, that infects mobile phones running the Symbian operating system, spreading via Bluetooth wireless. This was the first true mobile malware In March 2005, it was reported that a computer worm called Commwarrior-A had been infecting Symbian series 60 mobile phones. This specific worm replicated itself through the phone's Multimedia Messaging Service (MMS), sending copies to contacts listed in the phone user's address book. In August 2010, Kaspersky Lab reported the trojan Trojan-SMS.AndroidOS.FakePlayer.a. This was the first SMS malware that affected Google's Android operating system, and which sent SMS messages to premium rate numbers without the owner's knowledge, accumulating huge bills. Currently, various antivirus software companies offer mobile antivirus software programs. Meanwhile, operating system developers try to curb the spread of infections with quality control checks on software and content offered through their digital application distribution platforms, such as Google Play or Apple's App Store. Recent studies however show that mobile antivirus programs are ineffective due to the rapid evolution of mobile malware. Taxonomy Many types of common malicious programs are known to affect mobile devices: Expander: Expanders target mobile meters for additional phone billing and profit Worm: The main objective of this stand-alone type of malware is to endlessly reproduce itself and spread to other devices. Worms may also