Forensically-Sound Analysis of Security
Risks of using Local Password Managers
Joshua Gray
University of Derby
Virginia N. L. Franqueira
University of Derby
Yijun Yu
The Open University (presenter)
iRENIC 2016
@10:30-11:00September12,2016,FriendshipHotel,Beijing,China
Background
•  Passwordsremainthemostcommonformof
authenFcaFon
•  Alarge-scalestudy(2007)[1]suggeststhat:
•  Auserhas,onaverage,25onlineaccounts
requiringpasswords,and
•  Ausertypes8passwords/day
[1]D.FlorencioandC.Herley,“ALarge-ScaleStudyofWebPasswordHabits,”in
InProceedingsofthe16thInternaFonalConferenceonWorldWideWeb,
WWW’16.ACMPress,2007,pp.657–666.
Challengingtorememberpasswords
•  Humancapacitytorememberpasswordsis
affectedbymanyfactors:
•  Passwordcomplexity→strongerpasswords
arehardertorememberduetohighentropy;
•  Passwordmatching→whichpassword
belongstowhichaccount;
•  Frequencyofuse→rarelyusedpasswords
arehardertoremember;
•  Frequencyofchange→periodicchangesand
historychecksexacerbatetheproblem!
Howuserscopewiththeproblem?
•  Usersusedifferentstrategies:
•
•
•
•
Reusepasswords
Writepasswordsdown
Recycleoldpasswordswithsmallchanges
Usehighlyguessablepasswords
→Theseapproachesfavourusabilityover
security
SoluFon:PasswordManagers
•  PasswordManagershavebeen
recommended(e.g.,byCERT[7])asoneof
thebestwaystoaccommodatethetrade-off
betweenusabilityandsecurity
•  ItisbecomingbestpracFceforindividuals
andSMEs
[7]A.Huth,M.Orlando,andL.Pesante,“PasswordSecurity,ProtecFon,andManagement,”
UnitedStatesComputerEmergencyReadinessTeam,2012,
hhps://www.us-cert.gov/security-publicaFons/password-security-protecFon-andmanagement.
HowPasswordManagerswork?
Contextsofuse
Scopeofthisstudy
•  Explores3popularlocalpasswordmanagers
•  KeePassv.2.28
•  PasswordSafev.3.35.1
•  RoboFormv.7.9.12
•  Thesepasswordmanagerskeepadatabaseof
passwordslocaltothemachine(e.g.,
Windows7)runningit
Studystages
1.  ElicitaFonofsecurityrisks&Forensic
Soundness
•  Outcome:listofpotenFalrisks
2.  (Forensics)phasedtesFngapproach
•  Outcome:vulnerabiliFestousersofthe
studiedpasswordmanagers
–mayormaynotconfirmtherisks
Stage1:ElicitaFonofsecurityrisks
Stage2:PhasedtesFngapproach
Involvedthe
creaFonofa
baselinevirtual
machineforeach
PM(1GBRAM)and
runningthetest
casesusingthem.
Methodologyby
Carrier&Spafford
(2004)[30];EnCase
tool(v7.10.00.103)
wasused.
Whatwastested
Passwordmanager Testcases Aim
KeePass
PasswordSafe
RoboForm
K1-K4
Exercisemethodsofuserauthen;ca;on
K5&K6
Exerciseexportfeature
K7
Exerciseprintfeature
K8
Exerciseuninstallfeature
P1
Exercisemethodsofuserauthen;ca;on
P2
Exerciseexportfeature
P3
Exerciseclipboardfeature
P4
Exerciseuninstallfeature
R1
Exercisemethodsofuserauthen;ca;on
R2
Exerciseprintfeature
R3
Exerciseauto-completefeature
R4
Exerciseclipboardfeature
R5
Exerciseuninstallfeature
Confirmedrisksviaforensics:KeePass
Expectedresult
Actualresult(confirmedrisk)
K1
Datawillremain
WhenRAMislimited,themasterpasswordcanbefoundin
fullysecuredwithin theWindowspagefile(hiddenpagefile.sys)inplaintext.
thedatabase.
(r1)
K5
K6
Despitetheformat,
datawillbe
exported
encrypted.
Nosecurityclearancewasenforcedbeforetheexport
started;thedatabaseexportedinHTMLformatwas
unencryptedandcouldbeeasilyviewedinplaintextvia
browser;italsoremainedintheRecycleBinaYertheuser’s
requesttopermanentlydeleteit.(r1)(r4)
K7
Noresidueofthe
failedprin;ngwill
remaininthe
system.
Nosecurityclearancewasenforcedbeforetheprintstarted;
thedatabaseprintfilecouldbelocatedintheTempfolder
inplaintextaYeritfailedtoprint.(r1)
K7.1 Databasewillprint ThenewdatabasewasdeletedfromtheTempfolderaYer
andnoresidueofit successfullyprinted;however,theunsuccessfullyprinted
willremain.
databasefile(seeK7)remainedintheTempfolderinplain
text.(r1)
Confirmedrisksviaforensics:
PasswordSafe(P)&RoboForm(R)
Expectedresult
Actualresult(confirmedrisk)
P3
Thecopieddata
Thedatacopiedtotheclipboardremainedstoredinthe
willbedeleted
Windowspagefile(hiddenpagefile.sys)ofthecomputerin
fromtheclipboard. plaintextaYerthecomputerwasrebooted.(r1)
R1
Datawillremain
WhenRAMislimited,themasterpasswordcanbefoundin
fullysecuredwithin theWindowspagefile(hiddenpagefile.sys)inplaintext.
thedatabase.
(r1)
Summaryofrisks
•  WithaRAMof1GB,themasterpasswordforKeePassand
idenFtydetailsforpaymentusingRoboFormcanbefound
unencryptedinthepagefile;
•  TheexporteddatabaseinKeePassremainsintherecycle
binevenwhenusersconfirmitspermanentdeleFon;
•  UponunsuccessfulprintoutofKeePassdatabasedueto
trivialreasons,theunencrypteddatabaseremainsinthe
TempfolderevenaoerclosingtheapplicaFon,whichdoes
nothappenuponsuccessfulprintout;
•  Unencryptedsensi8vedatacopiedtoclipboardusing
PasswordSafecanbefoundinthepagefileaoer
rebooFngfromahard(non-graceful)shutdown.
Discussionpoints
•  SomevulnerabiliFesuncoveredareboundto
specialcondiFons(e.g.,paperrunningout,
poweroff)
•  However,theysFllrepresentriskssince:
•  thesecondiFonsarelikelytohappen,andare
someFmestrivial,and
•  malwarehasstartedtoexploitpassword
managers.
Discussionpoints
•  Citadel(2014)malware[36]recognisedtheuse
ofKeePassandPasswordSafeandtriggereda
keyloggertocapturethemasterpassword
•  HackingtoolKeeFarse[37]isabletodump
KeePassdatabasetoafileaccessibletoahacker,
whenauserislogged-in.
•  ToolslikePCT[34]canparsealiveNTFSsystem
andreconstructapagefile.
•  TheseshowthattheuncoveredvulnerabiliFes
representrealrisks.
Conclusion(1)
•  Thestudyalsoallowedustocompare&
contrastthebehaviourofthesethree
passwordmanagers
RecommendaFons:
1.  KeePassshouldadoptthepracFcebyPassword
SafeandRoboForm,andrequiresecurity
clearanceintheformatofauthenFcaFonbefore
processingdatabaseexportandprint,and
2.  PasswordSafeshouldadoptthepracFceby
RoboFormandencryptcontentcopiedtothe
clipboard.
Conclusion(2)
•  Packagedasvirtualmachines,suchtest
scenariosdescribedinthisworkcouldallow
regressionfortheimprovedpassword
managers.
•  Futurework,e.g.:
•  SincethetestcaseswerenotexhausFveand
notmanyfeaturesweretested,thestudy
scopeintermsoftestcasecoveragecouldbe
extendedorothersystemscouldbe
examined.
References
[1] D.FlorencioandC.Herley,“ALarge-ScaleStudyofWebPasswordHabits,”In:Proceedings
ofthe16thInternaFonalConferenceonWorldWideWeb.ACMPress,2007,pp.657–666.
[7] A.Huth,M.Orlando,andL.Pesante,“PasswordSecurity,ProtecFon,andManagement,”
UnitedStatesComputerEmergencyReadinessTeam,2012,
hhps://www.us-cert.gov/security-publicaFons/password-security-protecFon-andmanagement,lastvisited10/2014.
[30]B.D.CarrierandE.H.Spafford,“AnEvent-BasedDigitalForensicInvesFgaFonFramework,”
In:ProceedingsoftheFourthDigitalForensicsResearchWorkshop,2004,pp.1–12.
[34]S.Lee,A.Savoldi,S.Lee,andJ.Lim,“WindowsPagefileCollecFonandAnalysisforaLive
ForensicsContext,”In:theProceedingsofFutureGeneraFonCommunicaFonand
Networking(FGCN2007).IEEEPress,2007,pp.97–101.
[36]R.Lemos,“Malware’snewtarget:yourpasswordmanager’spassword,”November2014,
visited09/2015.[Online].Availableat:
hhp://arstechnica.com/security/2014/11/citadel-ahackers-aim-to-steal-vicFms-masterpasswords/
[37]D.Goodin,“HackingtoolswipesencryptedcredenFalsfrompasswordmanager,”
November2015,visited01/2016.[Online].Available:
hhp://arstechnica.com/security/2015/11/hacking-tool-swipes-encrypted-credenFals-frompassword-manager/