Google on Wednesday removes around a two dozens of apps from its Android Market after complaints that the concerned apps were secretly installing malware to steal users’ personal information.

The web search giant confirmed that it pulled twenty-one apps that included pirated versions of genuine Android software. The apps in question had been modified to embrace the malware and then made available via Android Market for free.

Collectively, the twenty-one apps were downloaded more than 50,000 times in a short period of around four days.

The malware used to steal users’ personal information like phone's unique IMEI number and send it back to a US-based server. In addition, it exploited security holes to root the handset and install a backdoor app to let further pirated software to be installed to the phone.

Another malware, called DreamDroid, has been discovered in even more apps that belonged to two publishers- Kingmall2010 and we20090202. Thses apps have also been removed from the Android Market.

Experts suggest that those who have run anyone of one of the malicious apps must reset their handsets to stock conditions to make it clean.