Top Banner
Looking Back on Three Years of Flash-based Malware Christian Wressnegger and Konrad Rieck EuroSec 2017 Belgrade, Serbia
16

Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Jul 09, 2020

Download

Documents

dariahiddleston
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Christian Wressnegger and Konrad RieckEuroSec 2017

Belgrade, Serbia

Page 2: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Malware

◾ Malicious software (Malware)◾ Lasting problem of computer security◾ Omnipresence of Trojans, Bots, Adware, …◾ Increase of targeted attacks using Malware

◾ Flash-based malware◾ Malware targeting the Adobe Flash platform◾ Drive-by-Downloads, malicious redirects, exploits, ...

Page 3: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Adobe Flash

◾ Flash is dead!◾ Deployed on 500 million devices across different platforms◾ Used on 25% of the top 1,000 Alexa web sites

◾ Dynamic and multimedia content on web pages◾ Advertisement, video streaming, gaming, …◾ 20 years of deployment◾ Powerful scripting language: ActionScript

Page 4: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Adobe Flash Vulnerabilities

◾ Increasing number of CVEs◾ About 1,000 different vulnerabilities in total◾ 2015: 329 new vulnerabilities (86% code execution)◾ 2016: 266 new vulnerabilities ( 73% code execution)

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

Year of occurrence

0

50

100

150

200

250

300

350

Nu

mb

er o

f C

VE

s

Page 5: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Retrospective View on Flash-based Malware

◾ 3 Years of Flash-based Malware◾ December 2013 – January 2017◾ 2.3 million unique Flash samples◾ Collected using VirusTotal

◾ Retrospective study only◾ Detection → GORDON (DIMVA 2016)

◾ How well has the malware been detected over the years?

Page 6: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Data Stream

◾ VirusTotal: 66 different virus scanners◾ Irregular scan intervals (samples are scanned when submitted)◾ Different number of scans per sample

0 100 200 300 400 500

Number of scans

10-1

100

101

102

103

104

105

106

Num

ber

of s

ampl

es

Page 7: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Benign vs. Malicious

◾ Use AV detections as collective label◾ Majority voting

is_malicious = (num_detctions >= t)

◾ Numerous examples in research– Drebin (NDSS 2014), GORDON (DIMVA 2016), MANTIS (CODASPY 2017), …

◾ Drawing a line is tricky◾ Mere thresholds are not enough (Hurier et al, DIMVA 2016)◾ However, detections stabilize over time (Kantchelian et al, AISEC 2015)

◾ Can we put this in concrete terms?

Page 8: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Temporal Change of Detection

◾ How badly does it change?◾ A lot in case there are only a few detections◾ Stabilizes over time and towards more consensus

Page 9: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

ZARKOV Sets

◾ Let’s have a look at “missed” sample, only◾ Not detected at first, but eventually flagged as malicious

– –

◾ Different manifestationsZ-1 Sharp line at 5 detectionsZ-2 Ignore scans with 5-9 detectionsZ-3 Not detected → detected by 10

T=(t 1, t 2)

Z={x|#initial (x)≤t1∧# final(x)≥t2}

T1 =(4,5)

T2 =(4,10)

T3 =(0,10)

Page 10: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Slipped Through the Net

◾ Condensed subset comprising (initially) missed malware◾ 2.3 million unique Flash samples

– Z-1: 3,321 → 0.14%– Z-2: 2,904 → 0.12%– Z-3: 814 → 0.04%

◾ That’s nice, but what's that in aid of?◾ Well, insight!◾ Interesting test cases for malware detection (Quality over Quantity?)

Page 11: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Temporal Distribution

◾ Broken down by month

◾ Sporadic highs.◾ Particularly noticeable: June/ July 2014◾ CVE-2014-0515 discovered in mid-April

Page 12: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Usage of ActionScript

◾ ActionScript used by samples in Z-1, Z-2, Z-3◾ Great majority uses ActionScript (version 3)

Dataset No AS AS-1 AS-2 AS-3

Z-1 0.5% 0.8% 1.4% 97.3%

Z-2 0.2% 0.4% 0.4% 99.0%

Z-3 0.2% 0.0% 0.4% 99.4%

Page 13: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Adobe Flash Versions

◾ Almost all platforms are targeted◾ AVM-1 is deprecated for more than 10 years◾ Great majority is targeting version 11.0 & 11.1 (mind the log-scale)

3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.1 10.2 10.3 11.0 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 21.0 22.0 23.0 24.0 25.0

Adobe Flash version number

0.1%

1%

10%

100%

Rel

ativ

e fr

eque

ncy

1996 - 2005(AVM1)

2011 2012 2013 2014 2015 2016

Z-1

Z-2

Z-3

Page 14: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Malware characteristics

◾ Other security relevant properties◾ Dynamic code, environment fingerprinting, long hex-strings, …

Page 15: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Summary

◾ Large-scale evaluation◾ 3 years of data (December 2013 – January 2017)◾ 2.3 million Flash animations

◾ Retrospective view on Flash-based malware◾ Evolution of detection over time

◾ ZARKOV sets◾ Not detected at first, but flagged as malicious eventually◾ Carving out interesting test cases

Page 16: Looking Back on Three Years of Flash-based Malware · 2017-05-01 · Looking Back on Three Years of Flash-based Malware Benign vs. Malicious Use AV detections as collective label

Looking Back on Three Years of Flash-based Malware

Institute of System SecurityChristian Wressnegger

@chwress http://sec.tu-bs.de/chris