Malware Analysis at AIRBUS Practical Considerations and Issues - - PowerPoint PPT Presentation

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Malware Analysis at AIRBUS Practical Considerations and Issues - - PowerPoint PPT Presentation

Malware Analysis at AIRBUS Practical Considerations and Issues July, 12th 2017 Xavier Mehrenberger, Raphal Rigo, Sarah Zennou Plan Introduction Automated analysis Machine learning experiments 2 M. Mehrenberger, R. Rigo, S. Zennou ::


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Malware Analysis at AIRBUS

Practical Considerations and Issues

July, 12th 2017

Xavier Mehrenberger, Raphaël Rigo, Sarah Zennou

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Plan

Introduction Automated analysis Machine learning experiments

  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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Context

  • high number of received binary samples
  • analyst time is in limited supply
  • ⇒ need automated analysis and triage
  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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Typical workflow of a malware sample

malicious? new? reverser

malware exotic malware binary SOC Security Operations Center

Our tools

  • Tools for automated malware analysis and triage, for SOC (Security

Operations Center)

  • Tools for manual analysis by reverser – including our own, BinCAT
  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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Plan

Introduction Automated analysis Machine learning experiments

  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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SOC Tasks

Incoming binaries processing

  • distinguish malicious from benign files;
  • determine what a malware sample does;
  • learn to recognize future similar samples (identify artifacts);
  • distinguish targeted malware from opportunistic ones (phishing, etc.);
  • give priorities on suspicious malware that have to be inspected by a

reverser Observation: targeted malware are much more unsual than opportunistic ones

  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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Infrastructure

REbus: communication bus (developed in-house, open source)

  • goal: make analysis tools cooperate!
  • exchange of typed messages (/binary/pe/%abc123...def)
  • independent programs may choose to process each message, based on type
  • decentralized processing & workflow
  • facilitates experimentation
  • scalable

Analysis agents

  • wrappers for existing tools
  • implementations of published techniques

Open source! https://github.com/airbus-seclab/rebus (agents will be published soon)

  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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Automated analysis (I)

Analysis automation

  • extract e-mails, archives
  • extract javascript from PDFs
  • extract macros from documents

Identification

  • sha256, . . .
  • exif data
  • document rendering
  • visual rendering (packer?)

Static metadata extraction

  • list imports
  • extract suspicious strings
  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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Automated analysis (II)

Signature matching

  • apply yara rules
  • antiviruses (IRMA)
  • signature-based identification techniques (peid, signsrch. . . )
  • query public databases (NSRL, virustotal)
  • common RAT configuration extraction tools

Dynamic analysis

  • run sample through several sandboxes
  • several OS images
  • collect and consolidate results
  • dubious behaviour detected by the sandbox
  • accessed files
  • resources: registry keys, mutexes, pipes. . .
  • network operations
  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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Plan

Introduction Automated analysis Machine learning experiments

  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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ML experiments

feature extraction hashing (minhash) distance computation classification goal: identify similar malware, classify into families

features

  • opcodes (using several disassemblers: IDA, objdump, jakstab, amoco)
  • strings
  • imports, . . .

combined feature extraction & distance computation algorithms

  • ssdeep
  • sdhash
  • simhash
  • bindiff, . . .
  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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ML Issues

  • issues:
  • feature choice
  • representative initial corpus to train your classifier
  • new samples may be completely different from what you already know (not

a physical process)

  • new samples have to be compared to every known sample Θ(n2)
  • typical data base are not well labelled (VT)
  • use analyst feedback in ML algorithms
  • application: identify near-identical new samples ⇒ reduce manual analysis
  • M. Mehrenberger, R. Rigo, S. Zennou :: Malware Analysis at AIRBUS

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