Google is automatically scanning apps submitted to Android Market for malware, following numerous reports highlighting how the lack of an approvals process is putting users at risk.

However, the search giant also countered these reports. “Between the first and second halves of 2011, we saw a 40 percent decrease in the number of potentially-malicious downloads from Android Market. This drop occurred at the same time that companies who market and sell anti-malware and security software have been reporting that malicious applications are on the rise,” it said.

According to the company, the service, codenamed Bouncer, provides automatic scanning of software without requiring developers to go through an approvals process akin to the one used by Apple and others.

Google said that Bouncer performs a set of analyses on new applications,  apps already in Android Market, and developer accounts.  It looks for known malware, spyware and Trojans, looks for behaviour which may indicate an issue, and compares against previously analysed apps to detect possible red flags.

The company said it actually runs apps on its cloud infrastructure to simulate how it will run on an Android device, and will monitor new developer accounts to prevent repeat offenders coming back.

In a blog post, Hiroshi Lockheimer, VP of engineering, Android, said: “No security approach is foolproof, and added scrutiny can often lead to important improvements. Our systems are getting better at detecting and eliminating malware every day, and we continue to invite the community to work with us to keep Android safe.”