RE: E-Card Remote Code Execution Scam

From: Jonathan A. Zdziarski (jonathanat_private)
Date: Sat Sep 28 2002 - 19:27:36 PDT

  • Next message: Fulton Preston : "RE: E-Card Remote Code Execution Scam"

    Well that is good to know that this is not some kind of trojan wanting
    to do damage (although installing adware on someone's machine without
    their knowing is almost as bad).  Hopefully nobody will try and use an
    idea like this for any worse purposes.
    
    I'd still be interested in knowing how someone using a fake address that
    doesn't exist was able to get a valid thawte certificate.  I thought
    they verified that information; I suppose it's possible they could've
    changed it after obtaining the certificate.  I find it odd that thawte's
    front-page propoganda is based on the word 'trust' and yet their own
    verification disclosure on their website claims that you should never
    assume anyone with a certificate is trustworty.  Go figure.
    
    
    -----Original Message-----
    From: Fulton Preston [mailto:fultonat_private] 
    Sent: Saturday, September 28, 2002 9:13 PM
    To: 'Jonathan A. Zdziarski'; incidentsat_private
    Subject: RE: E-Card Remote Code Execution Scam
    
    
    Using wget to grab the HTML I found the following in the html:
    
    <OBJECT width=0 height=0 ID="POTD"
    CLASSID="clsid:3750BFA3-1392-4AF3-AF86-9D2D4776E5A4"  
             codebase="e-card_viewer.cab#version=1,0,0,1">
    
    
    Using wget again, I grabbed e-card_viewer.cab from the site and unziped
    it.  It contained only one file: potd.dll
    
    I did a yahoo search for potd.dll and came across this at:
    http://and.doxdesk.com/parasite/Cytron.html
    
    Description
    Cytron is an Internet Explorer Browser Helper Object. It scans the
    content of pages being viewed for keywords and opens pop-up advertising
    when they are detected. 
    
    Also known as
    POTD, after the filename and BHO name; Burnaby, the internal object
    name; TargetingSource, the name used to describe the control in
    Downloaded Program Files. 
    
    Distribution
    Installed by ActiveX drive-by download on a page pointed to by mail
    claiming you have received an 'e-card'. The ActiveX control purports to
    be a viewer for e-cards. 
    
    What it does
    Advertising
    Yes. When IE is started for the first time it attempts to connect to
    Cytron's servers to download a list of keywords to look for, and URLs of
    pop-ups to open. 
    
    Privacy violation
    No. 
    
    Security issues
    No. 
    
    Stability problems
    None known. 
    
    Removal
    First deregister the Cytron BHO. Open a DOS command prompt
    (Start->Programs->Accessories) and enter the following commands: 
    
    cd "%WinDir%\System" 
    regsvr32 /u "%WinDir%\Downloaded Program Files\potd.dll" 
    You should then be able to delete the 'TargetingSource' entry in
    Downloaded Program Files (in the Windows folder), and the registry key
    HKEY_CURRENT_USER\Software\POTD (Start->Run->regedit). 
    
    
    
    Ran strings against the dll and it confirms the above stated.
    
    HKCR
    Burnaby.TargetingSource.1 = s 'TargetingSource Class'
    CLSID = s '{3750BFA3-1392-4AF3-AF86-9D2D4776E5A4}'
    Burnaby.TargetingSource = s 'TargetingSource Class'
    CLSID = s '{3750BFA3-1392-4AF3-AF86-9D2D4776E5A4}'
    CurVer = s 'Burnaby.TargetingSource.1'
    NoRemove CLSID
    ForceRemove {3750BFA3-1392-4AF3-AF86-9D2D4776E5A4} = s 'TargetingSource
    Class' ProgID = s 'Burnaby.TargetingSource.1' VersionIndependentProgID =
    s 'Burnaby.TargetingSource' ForceRemove 'Programmable' InprocServer32 =
    s '%MODULE%'
                val ThreadingModel = s 'Apartment'
    'TypeLib' = s '{4F80F72C-D6AE-412E-B859-E3EE4478BBC3}'
    HKLM 
       SOFTWARE 
       {
          Microsoft 
          {   
             Windows 
             {
                CurrentVersion 
                {
                   Explorer 
                   {
                      'Browser Helper Objects'
                      {
                         ForceRemove {3750BFA3-1392-4AF3-AF86-9D2D4776E5A4}
    = s 'POTD Helper'
                      }
                   }
                }
             }
          }
       }
    HKLM
       SOFTWARE
       {
          POTD
          {
             'POTD Helper'
             {
                ForceRemove CS
                {
                   ForceRemove Repositories
                   {
                      val 001 = s 'http://66.230.217.196/cybersex/trop.xml'
                      val 002 = s 'http://216.187.109.101/cybersex/trop.xml'
                   }
                }
             }
          }
       }
    HKEY_CURRENT_USER
       SOFTWARE
       {
          POTD
          {
             ForceRemove 'POTD Helper'
             {
             }
          }
       }
    MSFT
    stdole2.tlbWWW
    BURNABYLibWW
    8o TargetingSourceWd
    8ITargetingSource
    Burnaby 1.0 Type LibraryWW
    TargetingSource ClassW
    ITargetingSource Interface
    
    
    
    
    
    
    
    
    -----Original Message-----
    From: Jonathan A. Zdziarski [mailto:jonathanat_private] 
    Sent: Saturday, September 28, 2002 05:25
    To: incidentsat_private
    Cc: abuseat_private; server-certsat_private; abuseat_private
    Subject: E-Card Remote Code Execution Scam
    
    
    This seems an aweful lot to me like a Remote Code Execution Scam...
    
    I received an email addressed to "Undisclosed Recipients" notifying me
    that I received an E-Card today, so I went to the site
    http://www.surprisecards.net/viewcard.htm?id_num=[Undisclosed]&card=Pick
    +up to view the card.  Oddly, I received a security warning asking me if
    I wanted to allow some code to run on my machine.  Noticing the odd
    choice of form variables as opposed to other e-card sites (not to
    mention the fact that I could type in any number and get the same
    screen), and with an eyebrow now raised I went to the main website
    http://www.surprisecards.net to find "Welcome to the future home of
    richardoliver.web.aplus.net".  So I figure, if there's no way to send a
    card from this website then chances are nobody sent me a valid card.
    
    I took a look at the Thawte certificate for the card viewer "code" and
    got www.cytron.com, some no-name development website with nothing more
    than a phone number.
    
    At the moment I'm not in front of any sacrificial machine to test the
    card out on, but I suspect this email is being mailed out as a scam in
    an attempt to run arbitrary code on the user's machine using a valid
    Thawte certificate.  What the code does when it loads I've no idea as
    I'm not dumb enough to try it on my home machine.
    
    In summary, my suspicion that this is the case is based on the
    following:
    
    1. The email was from egreetingsat_private, yet was not redirecting me
    to a yahoo site.  (It was in fact coming from a yahoo mail server
    though).  
    
    2. The email was NOT from surprisecard.net
    
    3. The email was addressed to undisclosed recipients
    
    4. There is no medium for sending cards from this site
    
    5. www.cytron.com has no credible information about any card reader
    product or even the company.
    
    Perhaps someone in front of some extra hardware can take this and roll
    with it.
    
    
    
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