@danielfromclarkston
1. MegaBackup is a paid cloud storage & data-syncing service from Tortola, British. Its Windows version of download (md5, 522b0159a5c7f6827a9c599a06957f0c) has been detected as riskware, according to this Virustotal.com file report. Then remove it in time for good, and look for other better alternatives@ http://www.cnet.com/news/cloud-based-storage-options-for-mac-os-x/#! . Its Mac version is risk-free so far. For more, you can read this article.
2. Apparently, your Mac had been infected adware and browser hijackware. To address your issues, try doing the following below:
- save your personal data like your bookmark in Safari and/or other Mac version of browser, restore 'em to their factory value. Clean all temporary files. Reboot yr Mac. Check it out later. More, you can move that unwanted website into blacklist.
- Clean undesired apps. Run Activity Monitor ( http://www.howtogeek.com/227240/how-to-monitor-your-macs-health-with-activity-mo nitor/ ) , find out those apps' install path info, then terminate associated processes that match the mentioned app, such as "Reset Search". Use a valid app remover in the market if you're new to making changes to Mac, or uninstalling app manually.
- Scan yr Mac using an up-to-date antivirus app in the market.
3. Below are proactive security measures:
- Always be cautious when surfing, this helps prevent your Mac from being infected with fakealerts even scareware, such as "Your disk/system is at risk".
- Always perform a virus check before running or opening downloaded items. This can secure your Mac against adware even malware.
- Always slow down your mouse when installing 3rd-party apps. This helps keep unwanted bundled apps at bay.