Tag Archives: os x lion
One security and privacy feature of Mac OS X (includes Yosemite) that you might not know about is how to encrypt and password protect existing folders. The Disk Utility app allows you to create an encrypted disk image (and when mounted is called a “volume”) from an existing folder, thereby hiding the folder from prying eyes.
IMPORTANT: My suggestion is to use an obscure folder name when encrypting and password protecting existing folders – don’t use obvious names!
How to encrypt an existing folder:
- Launch > Disk Utility (use Spotlight or locate in /Applications/Utilities)
- Open Disk Utility – pull down > File menu and select > New and then > Disk Image from Folder
- Navigate to the folder you want to encrypt. Click > Image
- Set Image Format > read/write and > Encryption to “128-bit AES” (you can also use 256-bit AES but this will be slower to encrypt)
- Click > Where. This allows you to decide where to locate the .dmg disk image (volume) TIP: NEVER SAVE THIS FOLDER TO YOUR DESKTOP
- Click > Create – then set a password to access the folder (store this strong/long password in a password manager) – Password strength should be ‘Excellent’
If you click one of these fake Download buttons, you will be taken to a third-party commercial website. The fake Download button may also take you to a malware infected website and or automatically infect your computer with adware.
To get around not clicking the fake Download buttons, I use a free browser extension called AdBlock. This blocks banner ads, (annoying) video adverts, pop-ups and removes the fake Download buttons. If you use download mirror* websites, then AdBlock will be a very useful. Download mirrors have had a chequered history, especially when it involves bundling third-party tools such as Babylon Search Toolbar: Yahoo! Toolbar; Search Protect (Conduit) and Snap.do into genuine software without the developers consent.
Using AdBlock not only provides added security but it also speeds up the rendering of any website littered with various types of ads. You will instantly notice a faster browsing experience. Now, let’s guide you through how to setup AdBlock:
- To get started download AdBlock https://getadblock.com
- On AdBlock page, click Get AdBlock Now
In one of my earlier posts How to securely delete Mac OS X files in Trash basket you will have understood you can use a Mac OS X feature called “Secure Empty Trash”. This overwrites your data only once. Disk Utility v13 (517) offers a more aggressive and secure option called ‘Erase Free Space’ to securely delete data that has been deleted from recovery.
REMEMBER: It’s important to note that it’s actually possible to recover data that has been overwritten only once.
It’s worth pointing out that you can only use the ‘Erase Free Space’ option if you have a hard drive. If you are using a Mac with a Solid State Disk (SSD), this option will be greyed out. The reason for this is there is a finite amount of write operations that can be done before the SSD starts to wear. SSD manufacturers use something called “wear levelling” which extends the life of the SSD, so that the disk gets used evenly.
Computer files require to be overwritten if they are to be completely removed. So how can you do this securely, without leaving a single trace? Here is a simple method, which involves using Disk Utility (this app is built into Mac OS X):
Last week, it was claimed by security researchers that Shellshock was active in the wild and could potentially issue commands to a computer which would allow the attacker to gather information and or modify system files.
Most OS X users will be unaffected by the vulnerability, as Shellshock only targets users who have configured advanced UNIX services. So if you use terminal, or you look to spawn a shell like Perl or even use startup scripts, you will be affected. If you do use advanced UNIX services as described here, then you should update your OS X immediately.
You might use the App Store to update your OS X system, but in the event this bash update isn’t showing, you can download the appropriate OS X bash update 1.0 from the following links:
OS X bash Update 1.0 – OS X Mavericks http://support.apple.com/kb/DL1769
OS X bash Update 1.0 – OS X Mountain Lion http://support.apple.com/kb/DL1768
OS X bash Update 1.0 – OS X Lion http://support.apple.com/kb/DL1767
When you delete a file from a hard disk, the file isn’t erased, it’s just removed from the computer’s records. This rule applies to both PCs and Macs. If you decide to use the Mac Disk Utility 12.x or move files to Trash they are actually not erased. They are in fact just removed from the computer’s records.
Computer files require to be overwritten if they are to be completely removed. So how can you do this securely, without leaving a single trace? Here is a simple method, which involves using Disk Utility (this app is built into Mac OSX):
- Open Spotlight type > disk utility – you can also find it in the Utilities folder in Launchpad
- Click > Security Options and move the slider to > Most Secure (the slider is found in Mac OSX
- “Most Secure” – this writes over your data 7 times (with zeros) and is compliant with US DOD 5220-22 M standard
- Once you’ve chosen the above option click > Erase and then ….. wait
- Disk Utility will take some time (the time taken to erase your data depends on the amount of data that needs to be erased)