Saturday, December 31, 2011

Another Chinese Internet Fraudulent (yhoo-it.com)

While I was watching 'The Pacific' movie suddenly I just get a Yahoo Messenger popup message from my old friend (which is he's already Rest-In-Peace on Aug 2009 ago). This is interesting and kind of surprise for me while seeing my very close friend suddenly 'wake-up' from his long rest. I was monitoring this scammer about few months ago after surprising his online status. Check this out from the chatting using web browser YM:


From the given shortened URL it will redirect user to the following URL:

http://yhoo-it.com/?id=4ccda25f27843014&s=1&user=matkamil2000

The URL seem to be already expired. But soon it will appeared again. The actual website will appear some kind of offering  money that needs user to input their user name and email.


Let's take a look closer on the URL. The URL seem to be trying to fool the user that pretend it was coming from Yahoo. Based on whois information the URL was registered from China. Obviously.
Registration Service Provided By: Bizcn.com
Website: http://www.bizcn.com
Whois Server: whois.bizcn.com

Domain name: yhoo-it.com

Registrant Contact:
zhang yu
yu zhang sdfgsdfghf@msn.com
0463965823 fax: 0463965823
changhailu12hao
nanning guangxi 230254
cn

Administrative Contact:
yu zhang sdfgsdfghf@msn.com
0463965823 fax: 0463965823
changhailu12hao
nanning guangxi 230254
cn

Technical Contact:
yu zhang sdfgsdfghf@msn.com
0463965823 fax: 0463965823
changhailu12hao
nanning guangxi 230254
cn

Billing Contact:
yu zhang sdfgsdfghf@msn.com
0463965823 fax: 0463965823
changhailu12hao
nanning guangxi 230254
cn

DNS:
ns7.cnmsn.net
ns8.cnmsn.net

Created: 2011-12-04
Expires: 2012-12-04

The domain name seem to be newly registered and exactly the time I was start monitoring it. The domain has been pointed to two DNS ns7.cnmsn.net and ns8.cnmsn.net. The DNS server were also registered from China.
Registration Service Provided By: Bizcn.com
Website: http://www.bizcn.com
Whois Server: whois.bizcn.com

Domain name: cnmsn.net

Registrant Contact:
XiaMen Longtop Online Technology Co.,Ltd
huiping yi hpyi@longtoponline.com
+865922577888 fax: +865922577111
61, WangHai Road, Longtop Group Building, Xiamen Software Park
xiamen fujian 361008
cn

Administrative Contact:
huiping yi hpyi@longtoponline.com
+865922577888 fax: +865922577111
61, WangHai Road, Longtop Group Building, Xiamen Software Park
xiamen fujian 361008
cn

Technical Contact:
huiping yi hpyi@longtoponline.com
+865922577888 fax: +865922577111
61, WangHai Road, Longtop Group Building, Xiamen Software Park
xiamen fujian 361008
cn

Billing Contact:
huiping yi hpyi@longtoponline.com
+865922577888 fax: +865922577111
61, WangHai Road, Longtop Group Building, Xiamen Software Park
xiamen fujian 361008
cn

DNS:
dns.bizcn.com
dns.cnmsn.net
ns5.cnmsn.net
ns6.cnmsn.net
ns1.4everdns.com
ns2.4everdns.com

Created: 2003-08-08
Expires: 2015-02-27

Well, lets dig some more.
Nmap scan report for yhoo-it.com (109.230.222.53)
Host is up (0.29s latency).
rDNS record for 109.230.222.53: hosted.by.xsserver.eu
Not shown: 986 closed ports
PORT STATE SERVICE VERSION
25/tcp filtered smtp
80/tcp open http nginx 1.0.4
|_http-title: Site doesn't have a title (text/html).
|_http-methods: No Allow or Public header in OPTIONS response (status code 405)
111/tcp open rpcbind 2 (rpc #100000)
135/tcp filtered msrpc
139/tcp filtered netbios-ssn
443/tcp open ssh OpenSSH 5.5p1 Debian 6 (protocol 2.0)
| ssh-hostkey: 1024 6e:96:96:b1:aa:4b:e2:1a:e5:9f:35:9c:6a:79:af:df (DSA)
|_2048 48:bb:c1:d4:bf:08:4d:c6:41:30:ea:57:3e:eb:fe:19 (RSA)
445/tcp filtered microsoft-ds
593/tcp filtered http-rpc-epmap
1026/tcp filtered LSA-or-nterm
1027/tcp filtered IIS
4444/tcp filtered krb524
5432/tcp open postgresql PostgreSQL DB 8.4.1 - 8.4.4
6129/tcp filtered unknown
6580/tcp open parsec-master?
Device type: general purpose|WAP|router
Running (JUST GUESSING): Linux 2.6.X|2.4.X (95%), Linksys Linux 2.4.X (92%), Netgear embedded (92%), D-Link embedded (92%), Linksys embedded (92%), Peplink embedded (92%)
, Asus Linux 2.6.X (91%)
Aggressive OS guesses: Linux 2.6.23 - 2.6.33 (95%), Linux 2.6.35 (94%), Linux 2.6.31 (94%), Linux 2.6.32 (94%), Linux 2.6.22 (94%), OpenWrt White Russian 0.9 (Linux 2.4.3
0) (92%), Linux 2.6.18 - 2.6.27 (92%), Linux 2.6.31 - 2.6.34 (92%), Linux 2.6.34 (92%), Netgear DG834G WAP (92%)
No exact OS matches for host (test conditions non-ideal).
Network Distance: 9 hops
Service Info: OS: Linux

TRACEROUTE (using port 23/tcp)
HOP RTT ADDRESS
1 12.00 ms 60.53.173.202
2 16.00 ms 60.53.173.213
3 16.00 ms 60.53.173.213
4 228.00 ms 10.55.192.38
5 229.00 ms 10gigabitethernet1-3.core1.lax1.he.net (206.223.123.37)
6 290.00 ms 10gigabitethernet4-3.core1.nyc4.he.net (72.52.92.225)
7 333.00 ms 10gigabitethernet1-2.core1.lon1.he.net (72.52.92.242)
8 399.00 ms 10gigabitethernet4-2.core1.fra1.he.net (184.105.213.146)
9 290.00 ms hosted.by.xsserver.eu (109.230.222.53)

Since I don't trust any source from China even their web hosting provider, I make some Nmap scanning to seem what its got. The web server seem to be running on Unix machine with several web services port opened.

The Yahoo Messenger online status is coming from the expired phone number which probably has been taken by China scammer that live in Malaysia. Malaysia has multicultural country and it's not impossible that a Chinese from China can disguise as Chinese from Malaysia. Another thing is that probably the YM account has been stolen from his machine via malware infection.

More updates coming up soon.

Tuesday, December 6, 2011

MS Word Document (CVE-2010-3333) Exploit

A week ago as I checking for the new email and suddenly received an email with MS Word document as an attachment on my inbox (not spam box). This make me curious to know what the heck is that. Lets take a look closer. I rename the MSWord document to 'gigi.doc'. The .doc file size is about 160,192 bytes long.

The .doc file contain Rich Text Format (RTF) encoding format and we can see a lot of 0x41 slide until we found the exact shellcode within the slide character. Below show you the location of the exploit code in hex format:


As I convert the hex format to binary, we can see some interesting strings. I'm not sure why its trying to execute ping command to localhost. Well, after execute the malicious .doc file. It will create a file named csrss.exe (921C724CCB04B9F672B294FFFF83CE7B) and execute it then rename it to 'winword.exe'. Then it will launch the cmd.exe to execute the ping command to 127.0.0.1 with 1 byte. After that, the malware will execute a clean Word.doc file.

The running csrss.exe will create the Update.bat on user StartMenu startup folder with the following content:

Echo off
REG ADD "HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows" /v Load /t REG_SZ /d "C:\DOCUME~1\User\LOCALS~1\Temp\csrss.exe" /f
del %%0

The batch command file will add a startup into user Windows registry pointing to csrss.exe located in user temporary folder. Then, lets take a look through packet capture:


The captured packet show that the malicious file attempt to POST request to the following URL:
http://ymhz1.dyndns.biz:8080/
http://2011fm.dyndns.org:8080/
IP Addess: 114.248.90.120

The IP address was originated from China and still active at the time I was writing these. The csrss.exe will keep running on memory and sleep for every 60 second and check back to the given URL.

Note: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3333

Friday, December 2, 2011

W32/Ramnit.C Quick Analysis

I just received a laptop from a friend of mine that heavily infected with multiple viruses. I don't know how he can comfortably using it for few months until he felt so many annoying activities coming from the viruses. One of my interesting sample to be quickly analyze is W32/Ramnit. Based on few security blogs that I found this malware has been already discovered around April 2010. Let's check it out.

At the first detection I was notice that a lot of infections is coming from the HTML files (as Avira detecting so many HTML infection).

The HTML files contains a small VB Script that carrying embedded EXE files in Hex format that will drop in Windows temporary folder once user opening the infected HTML in their browser (only IE6 support VBScript). At the end of the infected HTML files seem to be a random garbage character in attempt to prevent a static size of HTML files.

Once the EXE file has been dropped, it will automatically execute the file. The EXE is about 108,032 bytes sizes (9B49FEC7E03C33277F188A2819B8D726). I'll explain quick going through what is the characteristic of the EXE file. The EXE has been compressed with UPX 3.03. Upon execution the following routine will be started:

  • Search for EXE, DLL and  HTML file extensions.

  • Infect all EXE and DLL by creating additional .text section on the PE file.

  • Infect HTML files by overwriting it with VBScript and Hexdecimal format of the EXE file.

The infected PE file will be create an additional PE sections called .text as shown on image below:


A large size of additional .text section (about 540kb) created which is contains a malicious code. The EP has been modify to execute malicous code first and point it back to actual EP to execute original code.

Manual cleaning for this type of malware probably impossible for end-user. Mass infection on users PC make it difficult to remove. The best way to fix it is either using NOD32  On-Demand Scanner (Portable) or format your Hard drive and installing new Windows.