Two legitimate-looking websites on the Google App Engine server are serving up adware to unsuspecting users.

The Google App Engine is a platform for developing and hosting web applications that also allows customers to register and host websites using the domain appspot.com.
The first appspot.com website prompted a free Java download for the executable file “Setup.exe” and appears very similar to the download page for Java.
When executed, users were told that they did not have the minimum system requirements as a means to hide malware installation, Barracuda Labs researcher Jason Ding said.
The second appspot.com website prompted the message, “A Media Player Update is Required to View this Content,” and users were once again prompted to download “Setup.exe,” which installed the adware.
Barracuda Labsdubbed the malware as "Solimba Adware."