December 17, 2008

Laptop Data Protection

Page 2 | microsoft.com/technet/SolutionAccelerators

Agenda

Scope of the problemData encryption toolkitLaptop threats discussion

Stolen government laptop held patient data Records of 2,500 taking part in a medical study went missing last month

Laptop Stolen With 22,000

Patients' Data

NHS laptop with 5,123 patient records stolen

Mental Health

Clinic Loses

Laptop Bearing

Patient Data

Up to 3,000 patients' data stolen

The details of up to 3,000

NHS patients could have

been on a computer stolen

from a doctors' surgery.

Hospital Chain

Loses Patient

Data

Stolen Laptop

Contains Unsecured

Data on 365,000

Patients

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“Workers will average nearly 40% of their time away from the

desk – a factor that will massively play into mobilizing millions of

corporate inboxes this year.”

Strategy Analytics, “Mobile business Application Outlook”, January 2006

“In 2006 we estimate the number of mobile professionals

(defined as spending at least 20% of their time away…) will

grow to roughly two thirds of workers.”

Strategy Analytics, “Mobile Business Application Outlook”, January 2006

“The worldwide mobile worker population is set to

increase to 878.2 million in 2009, accounting for

27.3% of the workforce.”

Strategy Analytics, “Mobile business Application Outlook”, January 2006

And so..

The Laptop Data Protection Solution Accelerator was born

The goal of the guide is to help customers secure the data on their mobile (and desktop) computers

http://technet.microsoft.com/en-us/library/cc500474.aspx

Microsoft Vision:

“When a customer loses a laptop, they only lose

a laptop.”

Trustworthy Computing:

“The security of our customers' computers and networks is a

top priority, and we are committed to building software and

services to better help protect our customers and the

industry.” Microsoft

The threats discussed in this presentation are not secrets

Our customers‟ adversaries are aware of these attack

vectors

Our customers need this information too, so that they may

make informed decisions about the level of data

protection that they need

Online attacks

With BitLocker, data is protected when the system is shutdown (protecting against offline attacks)

When the system is started, the keys are loaded and available in memory

Same thing if the system is in sleep mode (S3 standby)

Goal: Get the keys from memory

Online attacks..Warm Ghosting

Attacker boots systemAttacker warm reboots into OS which avoids destruction of RAM imageAttacker then can access ghost secrets in Memory

Cold Ghosting / Iceman attackPhysical memory cells may retain charge long enough to be copied

Battery backed DIMMs make it easy!Recent research made headlines but nothing “really” new…

http://citp.princeton.edu.nyud.net/pub/coldboot.pdf

Online Attacks..

Direct memory access via physical interfaces

PCI bus Exploit with PC Card & DMA (David Hulton, ShmooCon 2006)

Firewire / IEEE 1394 (allows physical access to host memory)

Firewire Attack

Adam Boileau, RuxCon 2006

Full Memory Dump via Firewireinterface

Leads to dump analysis to find the Bitlocker keys

Linux Target Vista, online

Firewire

Threats against the TCB

Core Root of Trust for Measurement (CRTM) is intended to be „immutable‟ portion of BIOS

Attacking the CRTM

Execute chosen-code in CRTM

Control / prevent measurements

Physically remove it

Attack existing CRTM (e.g. buffer overrun)

Attack secure update-mechanism to inject unauthorized code into CRTM

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Premeditated Attacks

Attacker hobbles BitLocker protection prior to laptop loss or theft

There are many advance-strikes

BitLocker does not protect against boot rootkits that are BitLocker-aware

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Bitlocker: Key Protection mechanisms

Security

Ea

se

of U

se TPM Only

“What it is.”

Protects

against: SW-

only attacks

Vulnerable to:

HW attacks

TPM + PIN

“What you

know.”

Protects

against: Many

HW attacks

Vulnerable to:

TPM breaking

attacks

Dongle Only

“What you

have.”

Protects

against: All HW

attacks

Vulnerable to:

Losing dongle

Pre-OS attacks

TPM +

Dongle

“Two what I

have’s.”

Protects

against:

Many HW

attacks

Vulnerable to:

HW attacks

TPM + PIN +

Dongle

“Two what I

have’s, One I

know.”

Vista SP1,

Server 2008

only

Advanced modes

Vista SP1\2008 Mitigations:Use bitlocker advanced modes with hibernation - Group policy for hibernateEnsure BIOS meets bitlocker standardsDisable 1394 and PCI host controllers

• http://blogs.msdn.com/si_team/archive/2008/02/25/protecting-bitLocker-from-cold-attacks-and-other-threats.aspx

Require smartcards for logon or use strong passwordsUse EFS + smartcard to protect user data

• After “x” bad tries, Smart Card locked FOREVER

Defence in depth:

EFS: Mitigates offline attacks except against user accountPrevents online attacks (on encrypted files)Threats switch to user‟s password

BitLocker with advanced modesPrevents offline attacks (replace passwords, read hashes)Threats switch to user logons

Ideal: BitLocker (+USB+Pin)+ EFS with Smart CardAttacker with notebook + Smart Card needs PINAfter “x” bad tries, Smart Card locked FOREVER

Pre-Vista SP1\2008:SYSKEY in mode 2 or 3 (can be used on XP\2000 etc) Key stored in your head (mode 2) Key stored on a floppy (mode 3)

Protects password hashes with 128 bit symmetric encryption Either mode prevents „Nordahl‟ boot-disk attacks Also prevents the DS Restore mode style attacks

Threat – Attacks on Passwords

Password guessing: Any services that exposes authentication protocols

are at risk for password guessing attacks

NetBIOS, SMB, RDP, IIS, FTP etc.

Online attacks:Dumping password hashes from LSASS while the operating system is running

• Pwdump*.exe, L0phtCrack 5, GSecDump• http://truesecurity.se/blogs/murray/default.aspxMust have admin access for this to work

Threats against Passwords

Man In the Middle AttacksSniffing shared-secret authentication exchanges based on a users password between client / server (LM, NTLMv2, Kerberos)

• Tools available for LM/NTLM and Kerberos v5: ScoopLM

BeatLM /Kerbcrack/ LC5

Threats against Passwords

MitigationsMake your hashes immune to reversing in any reasonable amount of time.

Use 10 (or 15) character or stronger complex passwords• Or better yet pass-phrases!

• NT based operating systems support 128 character pass-phrases

• Use two factor authentication

Change them every 90 days or less.

Minimum time before password can be changed 1 day

Number of previous passwords remembered: at least 24Run in least privilegeShutdown un-needed services (Server service, FTP service etc.)