"MegaBackup" is either an untrustworthy cloud-storage application or perhaps actual malware. I haven't tried to make that distinction.
To remove it, start by backing up all data (not with MegaBackup itself, of course.)
1. Quit the MegaBackup application, if it's running, and drag it from the Applications folder to the Trash. Don't try to empty yet.
2. Triple-click anywhere in the line below on this page to select it:
/Library/LaunchAgents
Right-click or control-click the highlighted line and select
Services ▹ Open
from the contextual menu.* A folder named "LaunchAgents" should open.
In the folder, there may be one or more files with a name beginning as follows:
com.WebTools
Move all such files to the Trash. You may be prompted for your administrator password.
3. This step is optional. Do as in Step 2 with this line:
~/Library/Application Support
You're opening a folder named "Application Support". Inside it, there may be a subfolder named "WebTools". Move that subfolder only to the Trash.
4. Log out or restart the computer and empty the Trash.
*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination command-C. In the Finder, select
Go ▹ Go to Folder...
from the menu bar and paste into the box that opens by pressing command-V. You may not see what you pasted because a line break is included. Press return.