I want Malware bites securiy application.

Hi James! Launchpad Answers is definitely a great place to ask questions, but sometimes it can take a bit longer. You can find out about the other support options at http://www.ubuntu.com/support :)

Ubuntu and Windows are different operating systems, which means that they provide distinct environments for the software you run. So, there is no version of MalwareBytes for Ubuntu. When you told to run it once a week, I'll bet that was because you were running Windows. At this point, you probably don't need it. Because Ubuntu doesn't run Windows software, it is not affected by Windows viruses, which are what MalwareBytes is designed to prevent. At the moment, there is really no risk of malware leaping on to your system through normal use. The situating here is basically that same as on MacOS, except we have the added benefit that Software Center provides a single central source for most of the stuff you need. That way, people don't need to download software from unreliable sources.

Some people still like to use virus scanners in Ubuntu, but this is usually to check that files they are relaying don't have viruses (because they can still affect Windows users). Quite useful for businesses, naturally. For that, we have ClamAV. You can find that if you open Software Center and type ClamAV into the search box at the top right. There will be a result named “Virus Scanner”, with a little diamond shaped logo.
It is also possible to buy Norton, Kaspersky Antivirus and a few others for Linux, though these packages are typically aimed at corporate use.