BKDR64_AGENT.GTY

 Analysis by: Alvin Bacani

 ALIASES:

Win64/Kryptik.EJ (ESET-NOD32)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware


This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It lowers the security setting of Internet Explorer.

  TECHNICAL DETAILS

File Size:

71,680 bytes

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

18 Oct 2013

Payload:

Connects to URLs/IPs, Compromises system security

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This backdoor drops the following component file(s):

  • "%User Temp%\{random folder name}\{random folder name}\wow.dll" - detected as BKDR64_AGENT.GTY

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

It drops the following non-malicious file:

  • "%User Temp%\{random folder name}\{random folder name}\wow.ini"

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

It injects itself into the following processes running in the affected system's memory:

  • Explorer.exe

It creates the following folders:

  • %User Temp%\{random folder name}\{random folder name}

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Autostart Technique

This backdoor modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_CLASSES_ROOT\CLSID\{fbeb8a05-beee-4442-804e-409d6c4515e9}\
InProcServer32
[Default] = "%User Temp%\{random folder name}\{random folder name}\wow.dll"

(Note: The default value data of the said registry entry is "%System%\SHELL32.dll.)

Other System Modifications

This backdoor adds the following registry entries:

HKEY_CURRENT_USER\Software\Classes\
clsid\{fbeb8a05-beee-4442-804e-409d6c4515e9}\inprocserver32
[Default] = "%User Temp%\{random folder name}\{random folder name}\wow.dll"

It adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
iehardenienowarn = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Setting
warnonbadcertrecving = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
warnonpostredirect = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
url history
daystokeep = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer
smartdithering = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer
autosearch = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\LowRegistry\DontShowMeThisDialogAgain
displaytrustalertdlg = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
noprotectedmodebanner = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
ie9runonceperinstallcompleted = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
ie9tourshown = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
smoothscroll = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
show image placeholders = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
usethemes = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
force offscreen composition = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
ZoneMap
ieharden = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\internet explorer\main
DisableFirstRunCustomize = "1"

Backdoor Routine

This backdoor connects to the following URL(s) to send and receive commands from a remote malicious user:

  • {BLOCKED}f.com
  • {BLOCKED}f.com

Web Browser Home Page and Search Page Modification

This backdoor lowers the security setting of Internet Explorer.

NOTES:

This backdoor is capable of encrypting the drop files using Windows Encrypting File System (EFS) feature.

The malware may also change the Security Properties of the drop files and created registries, to disable access to the files and registry.

Upon connection to the remote server, the backdoor may send the following to the remote location:

  • http://{BLOCKED}f.com/script.php?sid=8&q={keyword}&ref={ref}&={ua}&lang={lang}
where {keyword} could be either of the following:
  • average+cost+of+health+insurance+for+a+small+indiana+compnany
  • types+of+business+insurance+policies
  • free+grant+money+colleges
  • groupon+for+oil+change+in+new+jersey
  • aarp+term+life+insurance+rates
  • adt+home+security+systems+haines+city
  • do+small+tasks+online+make+money
  • adipex+p+prescriptionplus
  • how+to+apply+for+health+insurance+for+fiancee+visa+immigrant
  • merchant+credit+card+processing+lowest
  • what+is+the+snowball+effect+in+debt+reduction?
  • average+rate+quote+car+insurance+new+york
  • cost+qualified+high+deductable+health+insurance+plan
  • criminal+justice+degree+and+virginia
  • health+insurance+for+travellers+into+usa
  • london+ontario+memorial+boys+and+girls+club+offer+15%discount+to+car+insurance
  • order+a+credit+report
  • business+insurance+vehicle
  • criminal+justice+records
  • non+profit+consumer+credit+counseling+service
  • computer+science+bachelors+degree+online
  • fitness+weight+loss+houston
  • seap+debt+counseling+credit+card+processing
  • adipex+p+forums
  • broward+college+online+rn+program
  • auto+insurance+ontario+quote
  • global+debt+management
  • groupon+scandigital+03/14
  • hud+required+credit+reports+for+business+purposes
  • canadian+debt+settlement
  • credit+card+debt+settlement+online
  • at+home+business+nebraska
  • auto+car+cheap+insuran+insurance+allstate+insurance+georgia
  • oxford+health+insurance+family+coverage
  • renter+business+insurance
  • affordable+health+insurance+for+individual
  • home+alarm+systems+for+alzheimers+or+dementia
  • laptops+bad+credit+financing
  • understanding+construction+general+liability+insurance
  • payday+faxless+fast+cash+loan
  • free+credit+card+logos+for+business
  • good+debt+settlement+companies
  • online+auto+title+loans
  • buy+instantly+car+insurance+new+jersey
  • payment+processing+emerge+credit+card
  • attorneys+that+have+successfully+sure+auto+owners+insurance+company
  • free+health+insurance+pennsylvania+quote
  • is+groupon+a+fraud?
  • what+is+john+desmores+college+degree?
  • kennel+cough+doxycycline
  • klonopin+for+chronic+pain
  • debt+recovery+crbu
  • naugatuck+valley+community+college+online+courses
  • auto+insurance+quote+in+hudson+florida
  • health+insurance+defazio+coverage+refusal
  • competitive+quote+car+insurance
  • google+register+domain+names
  • domestic+partner+coverage+for+health+insurance+in+monroe+county+ny
  • debt+relief+laws
  • does+cancelling+a+credit+card+hurt+your+credit+rating
  • metlife+auto+insurance+quote
  • debt+settlement+customers+pa+19422
  • adipex+d c
  • reditcard+debt+reduction
  • hope+college+online+vet+assistant
  • inexpensive+accelerated+college+degree+programs
  • supervised+visitation+commercial+general+liability+insurance
  • quick+car+insurance+quote
  • hhgreggs+business+credit+cards
  • afba+life+insurance+complaint
  • general+american+life+insurance+class+action
  • uk+small+debt+recovery
  • accounting+for+life+insurance+policies
  • percent+of+sucessful+debt+reduction+programs
  • personal+loans+no+credit
  • paying+federal+income+tax+by+credit+card
  • self+help+credit+repair
  • irs+debt+relief+program
  • security+of+finanacial+transactions+with+credit+cards
  • colorado+non-profit+credit+card+donation+processing
  • emergency+medical+alarm+button
  • look+for+best+free+health+insurance+quotes
  • mobile+home+loans+for+poor+credit
  • credit+report+gov
  • can+you+be+denied+life+insurance+because+of+a+benig+brain+tumor
  • adipex+ingredient
  • cash+advance+loan+lenders
  • legitimate+debt+relief+company+pa+19422
  • easiest+college+degree
  • debt+reduction+negotiation
  • health+insurance+companies+for+the+state+of+new+york
  • credit+repair+firm+goldsboro+nc
  • online+psychology+degree+program
  • clinton+debt+reduction+social+security
  • credit+card+processing+compliance
  • low+income+housing+debt+reduction
  • signmaking+business+insurance
  • cheap+car+insurance+rates
  • job+related+health+insurance+coverage
  • best+health+insurance+for+people+50+or+older
  • cheap+pa+auto+insurance
  • senior+consumer+credit+counseling
  • the+best+international+flower+delivery+service
  • car+insurance+rates+comparison+ontario
  • debt+recovery+online+uk
  • jobs+that+dont+require+a+college+degree
  • historian+college+degree
  • groupon+las+vegas+to+hollywood
  • car+insurance+quotes+01376
  • credit+card+processing+fort+worth
  • how+much+does+car+insurance+cost+forcertain+cars
  • pensacola+debt+recovery
  • bike+insurance+quote+ontario
  • health+insurance+for+people+under+65
  • whos+the+new+band+on+free+credit+report+commercials
  • auto+insurance+companies
  • allstate+car+insurance+quote
  • auto+insurance+compare+quotes
  • grady+credit+card+processing
  • aplly+for+more+than+one+health+insurance
  • auto+insurance+quotes+toronto
  • compare+life+insurance+quotes
  • funeral+flowers+for+soldiers
  • community+college+minnesota+psychology+degree
  • online+degree+programs+for+certified+teachers
  • how+to+get+a+copy+of+your+childs+credit+report
  • car+for+cheap+insurance+for+17+year+old
  • easy+fast+lot+make+money
  • credit+card+debt+repair+agenties+in+knoxville+tn+are+they+honest
  • credit+repair+services+goldsboro+nc
  • online+college+degree+programs
  • california+business+insurance
  • health+insurance+coverage+alcohol+related+injury
  • best+individual+health+care+insurance+online+quotes
  • celebrex+and+antihistamine
  • car+insurance+vauxhall+quotes
  • buying+auto+insurance+online
  • federal+credit+card+debt+relief
  • nc+debt+settlement
  • what+credit+cards+pull+credit+reports+from+equifax+and+experian
  • car+insurance+imported+cars+uk
  • send+flowers+to+ashwood+vic
  • cheapest+domain+registration
  • groupon+coupons+phoenix
  • debt+relief+san+fernando+valley
  • groupon+village+of+baytowne+wharf
  • compare+work+at+home+jobs
  • aromatherapy+home+based+business
  • credit+repair+canada
  • health+insurance+for+high+risk+people
  • email+marketing+service
  • credit+cards+avaliable+for+good+credit+ratings
  • health+insurance+coverage+for+senior+expats
  • doctorate+of+engineering+online+degree
  • a+n+t+credit+cards+business
  • payroll+tax+debt+relief
  • kansas+city+groupon
  • online+degree+programs+univ+missouri+columbia
  • payday+cash+loans
  • credit+card+debt+relief+in+canada
  • adipex+buy+p
  • auto+insurance+companies+united+states+2013
  • pyxism+home+based+business+home+based+online+business+business+oppotunity+and+call+me
  • top+five+insurance+auto+companies+in+nm
  • glen+beck+college+degrees
  • broker+of+health+and+life+insurance
  • example+letters+to+dispute+credit+report
  • zambio+credit+card+processing+for+adult+paid+sites
  • hire+car+insurance
  • auto+insurance+quote+anonymous
  • complaints+about+freedom+debt+relief
  • classic+car+insurance
  • domain+registration+and+hostingaccredited+bachelor+degrees+online
  • comprehensive+car+insurance+quotes+in+australia
  • national+debt+relief+act
  • instant+online+auto+insurance
  • levaquin+class+action+suit
  • credit+card+van+business
  • 2013+health+insurance+for+adult+children
  • adipex+metairie+la
  • credit+card+consolidation+loans
  • auto+home+insurance+quotes
  • dental+care+credit+card
  • groupon+travel
  • health+and+dental+insurance
  • online+college+courses+bay+area
  • statistics+of+college+degree
  • cheapest+toronto+car+insurance
  • advertising+a+home+based+business
  • auto+insurance+quotes+dui
  • online+auto+insurance+estimates
  • 1st+insurance+health+insurance+quotes+in+london
  • home+and+auto+insurance+quotes
  • groupon+london+ontario
  • adt+home+security+system+reviews
  • perception+of+online+college+degrees
  • checks+unlimited+address+stamp+discount
  • provider+information+for+delaware+health+insurance
  • christian+college+degree+in+public+health+on-line
  • analysis+of+value+of+college+degree+vs+cost
  • credit+card+debt+settlement+facts
  • approved+funding+for+debt+management+agencies+from+irs
  • blue+cross+blue+shield+health+insurance+in+illinois
  • zehrs+health+insurance+coverage
  • how+long+to+charge+offs+stay+on+credit+report
  • credit+report+association+for+comcast+cable
  • debt+reduction+ohio
  • canada+debt+reduction
  • credit+card+debt+reduction+government+run
  • jazzercise+at+groupon
  • 2013+top+ranked+health+insurance+plans+california
  • aarp+health+insurance+for+seniors+with+pre-existing+conditions
  • national+groupon
  • pyxism+home+based+business+home+based+online+business+business+oppotunity+and+call
  • colorado+car+insurance
  • auto+insurance+companies+california
  • credit+card+debt+consolidation+florida+cds
  • credit+card+machines+uk
  • debt+consolidation+loan+payments
  • bears+college+degrees
  • car+insurance+company+just+woman
  • i+need+adipex
  • accutane+crohns+irritable+bowel
  • where+to+buy+fioricet+online
  • texas+largest+personal+auto+insurance+companies
  • debt+management+and+credit+counseling
  • top+careers+without+a+college+degree
  • online+college+classes+upper+michigan
  • business+credit+card+account
  • ajax+credit+card+processing
  • family+florida+health+insurance+plan
  • family+health+insurance+ohio
  • research+statistics+on+the+advantages+of+having+a+college+degree
  • complaints+on+auto+owners+insurance+company
  • criminal+justice+degree+at+bay+state+college+in+middleboro+massachusetts
  • groupon+inc.+chicagoil
  • fast+debt+relief
  • group+health+insurance+for+farmers
  • online+degree+programs+prophesy
  • merchant+services+credit+card+processing
  • effects+of+metformin+xr+on+blood+glucose+levels
  • st.+pauls+college+online
  • blue+cross+california+affordable+health+insurance+term+life
  • arizona+car+insurance
  • singapore+cheap+domain+name+registration
  • 10000+instant+personal+loan
  • chocolate+gift+baskets+richmond+bc
  • repair+credit
  • credit+report+and+charge+off
  • skaggs+consumer+credit+counseling+service+of+central
  • car+insurance+rate+low+cost+life+insurance+home+ow
  • think+debt+relief
  • credit+repair+consultant
  • buy+dinars+with+credit+cards
  • washington+state+universities+with+criminal+justice+degrees
  • insurance+net+low+auto+insurance+quote+from+top+ca
  • newloanrequest+fast+cash+personal+loans
  • debt+settlement+pennsylvania
  • 100+online+master+of+art+psychology+degree+programs
  • financing+business+using+credit+cards
  • groupon+roanoke+va
  • need+business+credit+cards
  • undergraduate+degree+in+environmental+engineering
  • college+degrees+for+the+real+world
  • auto+insurance+rate+in+salt+lake+city+metropolitan+life+insu
  • send+flowers+cheap+ct
  • quickbooks+credit+card+processing
  • what+is+a+state+farm+utility+rating+credit
  • business+insurance+phoenix
  • united+service+auto+insurance+company
  • dakota+free+group+health+insurance+quote+south
  • problems+receiving+payment+from+groupon
  • business+insurance+osha
  • mr+auto+insurance+company+in+jackosnville+fl
  • auto+insurance+quotes
  • debt+management+help
  • whats+the+difference+between+a+debt+consolidation+and+personal+loan
  • usbank+business+credit+cards
  • business+credit+cards+vermont
  • car+insurance+northern+ireland+abbey
  • toyota+used+car+warranty
  • cuyahoga+county+ohio+debt+consolidation+loans
  • what+health+insurance+company+will+cover+me+with+the+diagnosis+sleep+apnea?
  • california+cheap+health+insurance+quote
  • online+criminal+justice+degrees
  • credit+report+and+free
  • vicodin+detox
  • debt+settlement+company+regulations
  • debt+settlement+companies+that+purchase+consumer+debt
  • number+one+auto+insurance+company
  • car+insurance+rates+in+the+us
  • send+flowers+to+brazil
  • auxiliary+power+home+security+system
  • cheap+car+insurance
  • online+business+degree
  • auto+muscle+cars+insurance+companies
  • at+home+businesses+for+travel
  • chase+business+credit+cards
  • what+is+a+college+degree

    {ref} could any of the following:

    • http://www.iseek.com/iseek/search.html?query={keyword}
    • http://blekko.com/ws/?q={keyword}
    • http://duckduckgo.com/?q={keyword}

  •   SOLUTION

    Minimum Scan Engine:

    9.300

    FIRST VSAPI PATTERN FILE:

    10.350.03

    FIRST VSAPI PATTERN DATE:

    18 Oct 2013

    VSAPI OPR PATTERN File:

    10.351.00

    VSAPI OPR PATTERN Date:

    18 Oct 2013

    Step 1

    Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

    Step 2

    Identify and delete files detected as BKDR64_AGENT.GTY using either the Startup Disk or Recovery Console

    [ Learn More ]

    Step 3

    Delete this registry value

    [ Learn More ]

    Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

    • In HKEY_CURRENT_USER\Software\Classes\clsid\{fbeb8a05-beee-4442-804e-409d6c4515e9}\inprocserver32
      • [Default] = "%User Temp%\{random folder name}\{random folder name}\wow.dll"
    • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
      • iehardenienowarn = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
      • warnonbadcertrecving = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
      • warnonpostredirect = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\url history
      • daystokeep = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer
      • smartdithering = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer
      • autosearch = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\LowRegistry\DontShowMeThisDialogAgain
      • displaytrustalertdlg = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
      • noprotectedmodebanner = "1"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
      • ie9runonceperinstallcompleted = "1"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
      • ie9tourshown = "1"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
      • smoothscroll = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
      • show image placeholders = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
      • usethemes = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
      • force offscreen composition = "0"
    • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap
      • ieharden = "0"
    • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\internet explorer\main
      • DisableFirstRunCustomize = "1"

    Step 4

    Restore this modified registry value

    [ Learn More ]

    Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

    • In HKEY_CLASSES_ROOT\CLSID\{fbeb8a05-beee-4442-804e-409d6c4515e9}\InProcServer32
      • From: [Default] = "%User Temp%\{random folder name }\{random folder name}\wow.dll"
        To: [Default] = "%System%\SHELL32.dll"

    Step 5

    Reset Internet security settings

    [ Learn More ]

    Step 6

    Search and delete these folders

    [ Learn More ]
    Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  
    • %User Temp%\{random folder name}\{random folder name}

    Step 7

    Scan your computer with your Trend Micro product to delete files detected as BKDR64_AGENT.GTY. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

    Step 8

    Restore these modified registry values

    [ Learn More ]

    Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

    RESTORE
  • Close Registry Editor.

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