Sandbox vs manual analysis v2.1

Are malware sandboxes as good as manual analysis?

Michael Gough – FounderMalwareArchaeology.com

Co-creator of

MalwareArchaeology.com

Who am I• Blue Team Defender Ninja, Malware Archaeologist, Logoholic

• I love “properly” configured logs – they tell us Who, What, Where, When and hopefully How

Creator of

• Malware Management Framework

• Several Windows Logging Cheat Sheets

• Co-Creator of “Log-MD” – Log Malicious Discovery Tool

– With @Boettcherpwned – Brakeing Down Security PodCast• @BrakeSec

• @HackerHurricane and also my Blog


Malware evolves

• So must we

• Darwin says so

• Evolve or die

• Well… Evolve or get breached anyways

• Getting breached means an RGE !!!– Resume Generating Event


Define Sandbox

• A VM you build to evaluate malware

• An on premise virtual malware analysis like Cuckoo sandbox

• A specific malware analysis eco-system like RemNUX

• A cloud based malware analysis like Payload Security/ Reverse.IT, Lastline, Malwr.com, etc.

• Email Gateways like FireEye, Cisco AMP, etc.

• Web Proxies like FireEye, Lastline, etc.

• Advanced features in Firewalls like Palo Alto WildFire

• And of course anything you specifically build


Ways to bypass Automated Sandbox

Analysis


How do the malwarians evade sandbox analysis?

Look for indicators of a VM

• VM Tools

• Registry keys

• Hardware (is virtual not real)

Look for ‘Recent Files’

• Have you opened several misc. documents

Processor related indicators

• Some API calls take MUCH longer on a VM



Password protected files

• Can’t scan what you can’t access



OLE~

• Embed OLE objects and the sandbox may not know where to click to execute the payload



URL’s in the document

• Can be anywhere in the document



Time

• They wait you out

• Your automated queue will just backup

• How long can you wait? Or the automated sandbox wait?



Time

• They wait you out

• Your automated queue will just backup

• How long can you wait? Or the automated sandbox wait?



Time• The automated

sandbox gave up• So did our email

“Advanced Malware Protection”

But WE did not• +LOG-MD caught it

all


Manual Analysis rules• We detonate everything in a lab that fits a

pattern like ‘has a password’ and anything that comes back ‘unknown’ or ‘look incomplete


Manual Analysis rules


Manual Analysis rules

• We even found persistence


Time to disclose a Cloud provider that has had a

serious flaw ;-)


Hey, I got a FAX!!!

• Typical Phish

• A FAX.. SERIOUSLY?

• So 90’s…

• Word Doc attached

• Date: 08/30/16

• Time: 11:15am


Simple Manual Analysis

• 7-Zip

• Contains Macros



• Strings or Type

• Shows a Macro

• “Document_Open” shows autorun when the document is opened



• OfficeMalScanner – Seems malicious


Email Gateway


• Date: 08/30/16

• Time: 12:02pm

• 47 Mins later, another copy

CLEAN ???

And a couple more…

• Clean???


VawTrak

Even AV actually caught it

• Same Day !

• McAfee knew


VawTrak


• In 1 minute or less I was able to tell this Word DOC is malicious with very basic analysis– 7Zip, Strings & OfficeMalScanner

• To be certain the file is bad, we could detonate it in a lab or an online solution

• Let’s see what the fancy pants Cloud and Sandbox solutions say about it

• By the way, auto processing your documents to the cloud may contain PII ;-(


VirusTotal

• VT Score 28/53

• Date: 9/8/16

• 8 Days later

• AV has a Sig

• Clearly BAD


Unknown???


• This is obviously bad Word Doc, same as the others

• This one had the added benefit of an embedded OLE object

• Still easily bad

• This one was KOVTER

Let’s see what a

Cloud analysis shows


Reverse.IT


Reverse.IT


Reverse.IT


Artifacts / Indicators• What do we want to get out of any analysis?

– URL’s What websites were visited– IP’s Communications– Filenames What files were added– Directories used Where does it live– Autoruns used How does it launch– Config changes What changed– Metadata Details– Signed Digital Signatures– Behavior What actually happened– Network info Traffic behavior - Net Flow


Artifacts / Indicators

• Why do we want this data?

• We need to know who else got infected

– The IP’s and URL’s

• What was added

• What was changed

• So we know whether to

– Re-image

– IF we can clean it up


Let’s look at another Manual analysis


Artifacts URL’s• A little script I run during analysis

• And…

• Google


Process Artifacts

• What launched

• Linked processes – Bad EXE calls WinHost32.exe


CreatorID

ProcessID

Process Name

Sandbox Found

Artifacts IP’s

• What talked to Whom

• Wait… WinHost32 did not show up in the Cloud Analysis


File & Dir Artifacts

• Files involved

• Directories involved


Persistence

• Run Key created


Artifacts - Sysmon

• What loaded the image

• Signed or not

• Hashes


• Another little script I run


Let’s compare

Manual to Cloud


Artifacts / Indicators

– URL’s

– IP’s

– All Filenames

– All Directories used

– Autoruns used

– Config changes

– Metadata

– Signed

– Behavior


No/Yes Yes

No Yes

Some Yes

Some Yes

No Yes

No Yes

Yes Yes

Yes Yes

No Yes

Cloud Manual

Sandbox or Manual?

• Paid solutions work better than Free ones

• Many samples failed to execute due to VM aware

• Not as much detail as you can get yourself (IMHO)

• You CAN do as good a job, or better as sandbox solutions

• Sandbox solutions are good for multiple samples after you have evaluated one using manual analysis so you can compare results

• You may, or will have to super harden VM sandboxes to make them look and act like a normal system


So what do we use for manual analysis?


Free Edition


• Audit your settings – Do you comply?

• Harvest security relevant log data

• Whitelist log events by IP, Cmd Line, Process and File / Registry audit locations

• Perform a full File Baseline of a system

• Compare a suspect system to a Baseline or Dir

• Perform a full Registry snapshot of a system

• Compare a suspect system to a Reg Baseline

• Look for Large Registry Keys for hidden payloads


• Everything the Free Edition does and…• More reports, breakdown of things to look for• Specify the Output directory• Harvest Sysmon logs• Whitelist Hash compare results• Whitelist Registry compare results• Create a Master-Digest to exclude unique files• WhoIs lookups of IP Addresses called• SRUM netflow data (Win 8.1 & 10 64bit)

• Free updates for 1 year, expect a new release every quarter• Manual – How to use LOG-MD Professional


Future Versions – In the works!• PowerShell details

• AutoRuns report• VirusTotal lookups of discovered files

• Find parent-less processes• Assess all processes and create a Whitelist• Assess all services and create a Whitelist• VirusTotal lookups of unknown or new processes and

services• Other API calls to security vendors

So what do we get?


• WHAT Processes executed

• WHERE it executed from

• IP’s to enter into Log Management to see WHO else opened the malware

• Details needed to remediate infection

• Details to improve your Active Defense!

• I did this in…

15 Minutes!

Resources


• Websites– Log-MD.com The tool

• The “Windows Logging Cheat Sheet”– MalwareArchaeology.com

• Malware Analysis Report links too– To start your Malware Management program

• This presentation is on SlideShare and website– Search for MalwareArchaeology or LOG-MD

Questions?


You can find us at:

• Log-MD.com

• @HackerHurricane• @Boettcherpwned

• MalwareArchaeology.com• HackerHurricane.com (blog)• MalwareManagementFramework.Org

• http://www.slideshare.net – LinkedIn now

Technology

Sandbox vs manual analysis v2.1