Difference between revisions of "Mac OS X"

Revision as of 10:33, 25 June 2014

Apple Inc.'s Macintosh OS X (pronounced "OS Ten") is the operating system distributed with Apple computers. It includes heavily used several programs by default, including Apple Mail, a web browser called Safari, and an Apple Address Book, and iCal.

EFI boot

The firmware is responsible for initializing the hardware and performing a POST (Power-On Self Test).

The default boot volume is stored in NVRAM and can be configured through the "Startup Disk" preference pane or the nvram command line utility [1]. Additional boot arguments can be provided via the "boot-args" value [2].

Mac OS X estends EFI with a read-only HFS+ driver.

HFS+ volume header fields are used to point to a "blessed file" to be loaded as an EFI application.

Mac OS X EFI boot process supports both MZ-PE/COFF and EFI fat binary type executables.

/com.apple.recovery.boot/boot.efi
/System/Library/CoreServices/boot.efi
/usr/standalone/i386/boot.efi

The behavior of boot.efi can be configured in the com.apple.Boot.plist [3] which can be found in:

/Library/Preferences/SystemConfiguration/

Disk image types

Mac OS X has support for various disk image types build-in, some of which are:

• read-write disk image (.dmg) some of which use the Raw Image Format
• Sparse disk image (.spareimage)
• Sparse bundle disk image (.sparsebundle)

Burn Folder

Mac OS X Burn Folder:

$NAME.fpbf

This folder normally contains alias files (similar to LNK files under Windows). Which should have the following signature.

00000000  62 6f 6f 6b 00 00 00 00  6d 61 72 6b 00 00 00 00  |book....mark....|

These alias files contain additional date and time values.

Also check the following files for references to deleted .fpbf paths:

/Users/$USERNAME/Library/Preferences/com.apple.finder.plist
/Users/$USERNAME/Library/Preferences/com.apple.sidebarlists.plist

Actual burning of optical media is logged in:

/var/log/system.log
/Users/$USERNAME/Library/Logs/DiscRecording.log
/private/var/.logs_exporter/cache/Users/$USERNAME/Library/Logs/DiscRecording.log

HFS/HFS+ date and time values

In HFS+ date and time values are stored in an unsigned 32-bit integer containing the number of seconds since January 1, 1904 at 00:00:00 (midnight) UTC (GMT). This is slightly different from HFS where the date and time value are stored using the local time. The maximum representable date is February 6, 2040 at 06:28:15 UTC (GMT). The date values do not account for leap seconds. They do include a leap day in every year that is evenly divisible by four. This is sufficient given that the range of representable dates does not contain 1900 or 2100, neither of which have leap days. Also see: Technical Note TN1150 - HFS Plus Volume Format

Converting HFS/HFS+ date and time values with Python:

import datetime

print datetime.datetime( 1904, 1, 1 ) + datetime.timedelta( seconds=0xCBDAF25B )

Launch Agents

System-wide:

/Library/LaunchAgents
/System/Library/LaunchAgents

Per user:

/Users/$USERNAME/Library/LaunchAgents

These directories contain Property list (plist) files.

Launch Daemons

System-wide:

/Library/LaunchDaemons
/System/Library/LaunchDaemons

These directories contain Property list (plist) files.

Startup Items

/Library/StartupItems/
/System/Library/StartupItems/

Crash Reporter

/Library/Application Support/CrashReporter

Contains text files named .crash, .diag, .spin

Diagnostic Reports

/Library/Logs/DiagnosticReports

Internet Plug-Ins

System-wide:

/Library/Internet Plug-Ins

Per user:

/Users/$USERNAME/Library/Internet Plug-Ins

Quarantine event database

See [4]

Snow Leopard and earlier

/Users/$USER/Library/Preferences/com.apple.LaunchServices.QuarantineEvents

SELECT datetime(LSQuarantineTimeStamp + 978307200, "unixepoch") as LSQuarantineTimeStamp, LSQuarantineAgentName, LSQuarantineOriginURLString, LSQuarantineDataURLString from LSQuarantineEvent;

Lion and later

/Users/$USER/Library/Preferences/com.apple.LaunchServices.QuarantineEventsV2

sleepimage

This file is similar to the hibernation file on Windows.

/private/var/vm/sleepimage

Also see: [5]

Last shutdown logs

/private/var/log/com.apple.launchd/launchd-shutdown.system.log
/private/var/log/com.apple.launchd/launchd-shutdown.system.log.1

Package Files (.PKG)

Package Files (.PKG) are XAR archives [6] that contain a cpio archive and metadata [7].

Also see

• MacOS Process Monitoring
• Acquiring a MacOS System with Target Disk Mode
• Converting Binary Plists
• FileVault Disk Encryption
• File Vault

Formats

• Basic Security Module (BSM) file format
• Property list (plist)

External Links

• Official website
• Wikipedia entry on OS X
• Quarantine event database
• Mac Forensics: Mac OS X and the HFS+ File System by P. Craiger
• Mac OS X Directory Services Integration including Active Directory
• NSKeyedArchiver files – what are they, and how can I use them?
• Command Line ALF on Mac OS X
• Demystifying the DMG File Format
• mac-security-tips

Apple Examiner

• The Apple Examiner
• USB Entries on OS X
• Macintosh Forensics - A Guide for the Forensically Sound Examination of a Macintosh Computer by Ryan R. Kubasiak

EFI

• The Intel Mac boot process, by the rEFIt project
• Carving up EFI fat binaries, by snare, February 24, 2012

iCloud

• iCloud: iCloud security and privacy overview