EIP RevisitedExploitation & Defense in 2013

Dan Guido – BruCon – 09/26/2013

Introductions

@dguido

Exploit Intelligence Project

Intel-driven case study from 2011 How do we use intel to mitigate a threat? What are optimal defenses for mass malware? How do crimepacks acquire exploits? Is security research being applied by

crimepack authors? Separate what could happen from what is

happening

Clear Market Leaders

NeoSp

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CRiMEPACK

Libert

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WebAtta

cker

Eleon

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gusSib

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JustEx

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Bleedin

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SEO Ex

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ZombieGpa

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Phoe

nixUniq

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Limited Target Support

5

5

21

Flash / ReaderJavaInternet ExplorerQuicktime

Low Quality Exploits

Memory Corruption (19)Defeated by DEP 14Defeated by ASLR 17Defeated by EMET 19

Logic Flaws (8)No Java in Internet Zone 4No EXEs in PDFs 1No Firefox or FoxIt Reader 2

Developed Elsewhere

DEP Bypasses (5)Developed by APT 3Developed by Whitehats 2Developed by Malware Authors 0

Logic Flaws (8)Discovered by APT 0Discovered by Whitehats 8Discovered by Malware Authors

0

Java is a Path Forward

Malicious

HTML

GoogleChrome

IE8DEP/ASLR

Bypass

DEP/ASLR

BypassSandbox Escape

Integrity Escalatio

n

Java

Shell

Derived Optimal Defenses

Recommended to defend against crimepacks in 2011:1. Enable DEP on browser and plugins2. Remove Java from Internet Zone3. Secure Adobe Reader configuration4. Use EMET when possible / where needed

Then, continue to monitor threat intel for changes…

Where are they now?Crimepacks in 2013

Crimepacks in 2013

Standard desktop builds use DEP/ASLR/Sandboxes 2009: Windows XP, IE7, Flash 9, Office 2007,

Java 6 2013: Windows 7, IE9, Flash 11, Office 2010,

Java 7 Blackhole / Cool, Sweet Orange, and Gong Da

Have these kits invested in bypassing our new defenses?

How have crimeware packs dealt with the pressure?

The World is Changing

2011

-01

2011

-04

2011

-07

2011

-10

2012

-01

2012

-04

2012

-07

2012

-10

2013

-01

2013

-04

2013

-0705

101520253035

IE 6.0IE 7.0IE 8.0IE 9.0IE 10.0

Source: StatCounter January 2011 – August 2013 Browser Versions

Supported Targets

3

5

1

9Reader / FlashInternet ExplorerWindows TTF FontJava

Windows XP Only

Close Encounters of the EIP Kind

Crimepacks acquire capabilities for Windows 7+ through divine intervention

Exploit Origins

VUPEN Blog ArticlesAPT CampaignsSecurity Researchers

• All memory corruption exploits came from APT campaigns or the VUPEN blog.

• All Java exploits came from security researchers:• Jeroen Frijters• TELUS Security Labs• Adam Gowdiak (Security

Explorations)• Stefan Cornellius• Sami Koivu via ZDI• Michael Schierl via ZDI

• “Whitehats Shrugged”

IE / FlashJava

Cool Exploit Kit

Premium version of Blackhole, by the same author Launched a $100k bug bounty for improved exploits Only offered as a hosted service to prevent source leaks

As a result, Cool has several unique exploits: CVE-2011-3402: Windows Kernel TTF font (Duqu) CVE-2012-1876: IE 9 (VUPEN Pwn2Own) CVE-2012-0775: Reader 9/10 (self-developed)

Relies upon payload for privesc (ex. in caberp source)

How’d we stack up?

DEP, remove Java, secure Reader, EMET as necessary Safe from all but TTF font exploit w/o patching!

Systems being deployed now w/o Java are out of reach Win7, IE9, Reader X, EMET as necessary

Mixed messages coming from this data Success! We have pushed crimepacks to the margins Warning! It is easy to predict if you will get owned

The Advanced Persistent Threat

How effective are exploit mitigations against this threat?

Aurora et al.

Highly regarded technical capabilities Prolific developers of zero-day exploits Original source for many crimepack exploits Pioneered “watering hole” attack campaigns Notable for successful compromises of Google,

Bit9 Continues to cross paths with Trail of Bits

Exploit profiled in Assured Exploitation Elderwood Exploit Kit dissection and analysis

Elderwood

Think, a “startup” for Aurora to invest in Developed several reusable vuln disc / exploit tools Requires less-skilled people to operate the tools Launch zero-day watering holes on a regular basis

Released new attacks every ~3 months in 2011/2012 4 Internet Explorer, 5 Adobe Flash zero-days Dozens of prominent websites compromised (CFR)

Quality Exploits?

Elderwood

50% of the time

Flash, Java, and Officeplugins available

Internet Explorer 8

All Computers

Modest exploit mitigations are surprisingly effective!

Meet NYU-Poly…

… and Davis

It’s Easy to Get Better

Elderwood NYU-Poly Davis

Plugins Required

Flash, Office, Java

.NET None

Version Support

IE8 / Win XP IE8 / Win7 IE9 / Win7

Reliability ~50% ~95% ~99%

Features Hardcoded ROP Hardcoded ROPASLR Bypass

Dynamic ROPASLR Bypass

Time to Develop

? (probably 8 hrs)

~5 days ~10 days

Experience Professional Amateur Amateur

Reality

RSA – phishing email with malicious Excel doc Exploited Flash vuln no longer viable in IE

Google – IE6 in remote office to total control of Gmail They found the ONE guy in Google using IE6

Amateurs push as hard as they can. Professionals push as hard as they have to. Rapid discovery and shift to low cost attack vectors

APT Discoveries

Maybe we should try to make protections that cannot be bypassed by CS undergrads with 40 hrs of training?

We need to push harder since the professional bad guys can own things without caring about mitigations

APT can get better, we know they will, but is it prudent not to act just because you know they will respond?

Taming the TigerUse the Kill Chain and Courses of Action the way they were

intended

Variety of Approaches

Drag picture to placeholder or click icon to add

“An APT breached my network despite my $750,000 IPS and $2,000,000 SIEM. What other vendor products should I buy to

protect myself?” –Jerkface

External Exposure

Phishing Resistance“99% of the security breaches it investigated in 2012 started with

a targeted spearphishing attack.” –Mandiant“If you go from 35 to 12% on fire, you’re still on fire.” –Zane

Lackey

Exploitability

Final Conclusions

Let’s make defenses that bored undergrads can’t take out in one semester, that would be cool!

Let’s build things that help understand your adversary’s capability and intent.

Let’s use the defenses we have. They work, and they work against the people you care about.

Thanks Andrew Ruef and Hal Brodigan!

References

Contagio: An Overview of Exploit Packs http://contagiodump.blogspot.com/

2010/06/overview-of-exploit-packs-update.html Elderwood Kit Analysis

http://blog.trailofbits.com/2013/05/13/elderwood-and-the-department-of-labor-hack/

Detecting Targeted Malicious Email Rohan Amin