W32.Waledac

The worm may arrive on the computer as an attachment to spam email or through a link to a malicious Web site.

The email attachment has the following name:
ecard.exe

When the worm executes, it creates the following registry entry so that it executes whenever Windows starts:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\"PromoReg" = "[PATH TO THREAT]"

It also creates the following registry entries:

• HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\"RList" = "[HEXADECIMAL DIGITS]"
• HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\"MyID" = "[HEXADECIMAL DIGITS]"

The worm searches for email addresses in all files on both fixed and removable drives, except files with the following extensions:

• .7z
• .avi
• .bmp
• .class
• .dll
• .exe
• .gif
• .gz
• .hxd
• .hxh
• .hxn
• .hxw
• .jar
• .jpeg
• .jpg
• .mov
• .mp3
• .msi
• .ocx
• .ogg
• .rar
• .vob
• .wav
• .wave
• .wma
• .wmv
• .zip

It may also connect to some of the following IP addresses:

• 116.122.25.144
• 116.16.203.123
• 116.254.87.118
• 116.73.41.45
• 116.74.181.12
• 118.101.212.97
• 118.39.80.191
• 119.1.16.8
• 119.154.9.151
• 119.99.195.58
• 121.243.167.55
• 124.115.101.170
• 124.13.227.4
• 124.21.244.186
• 124.79.29.116
• 125.163.244.92
• 125.36.151.115
• 125.41.87.82
• 125.45.67.194
• 148.245.125.199
• 151.33.215.0
• 165.194.27.11
• 189.41.17.132
• 189.41.30.130
• 189.42.164.145
• 194.120.84.9
• 199.203.64.235
• 200.120.152.186
• 200.125.92.244
• 200.165.243.185
• 200.55.160.124
• 200.82.185.119
• 201.212.68.161
• 201.216.3.229
• 201.231.145.111
• 201.27.196.253
• 201.79.228.217
• 209.83.88.3
• 209.87.251.55
• 210.119.19.61
• 212.69.49.12
• 213.66.99.225
• 217.129.86.162
• 217.26.165.146
• 220.224.231.73
• 221.223.130.74
• 24.116.119.157
• 24.209.2.161
• 24.222.92.246
• 24.24.186.141
• 24.82.3.140
• 60.218.245.51
• 60.31.94.54
• 61.102.212.18
• 61.238.16.83
• 64.184.89.202
• 68.41.238.247
• 68.91.129.102
• 69.37.168.16
• 70.61.170.203
• 71.121.79.208
• 72.177.194.167
• 72.24.203.145
• 72.241.49.144
• 72.38.168.67
• 76.124.149.22
• 76.25.195.117
• 76.89.100.221
• 76.9.39.158
• 77.109.39.105
• 77.252.98.96
• 77.29.194.238
• 77.65.140.248
• 77.81.248.158
• 80.117.119.193
• 80.183.57.117
• 80.232.245.52
• 80.66.240.179
• 81.111.41.240
• 81.172.96.184
• 81.18.72.138
• 81.184.102.33
• 81.31.167.5
• 81.31.183.214
• 81.84.31.144
• 82.154.44.107
• 82.233.183.147
• 82.56.63.197
• 82.61.43.115
• 82.78.142.146
• 83.131.228.111
• 83.132.209.172
• 83.191.233.15
• 83.31.140.66
• 84.109.6.14
• 84.122.132.201
• 84.125.99.94
• 84.16.228.132
• 84.228.137.182
• 84.237.134.103
• 84.26.190.246
• 84.3.93.129
• 85.130.29.52
• 85.130.30.117
• 85.133.206.120
• 85.152.62.104
• 85.185.119.42
• 85.196.183.244
• 85.201.43.175
• 85.232.254.214
• 85.255.109.83
• 85.64.79.166
• 86.100.217.214
• 86.107.149.138
• 86.126.20.9
• 86.126.37.96
• 86.4.67.129
• 86.66.131.160
• 87.110.51.157
• 87.16.10.84
• 87.5.40.197
• 87.67.94.212
• 87.69.73.78
• 87.69.83.37
• 87.97.40.218
• 88.148.101.139
• 88.160.7.118
• 88.222.201.105
• 89.1.27.149
• 89.138.89.17
• 89.141.52.164
• 89.160.77.132
• 89.165.120.134
• 89.165.68.177
• 89.165.78.95
• 89.39.168.174
• 89.45.136.200
• 89.74.204.108
• 89.75.11.4
• 89.77.53.132
• 92.112.248.195
• 92.249.152.117
• 93.126.72.83
• 93.172.160.70
• 93.177.144.51
• 98.197.170.70
• 98.221.243.14
• 99.144.153.58
• 99.236.47.238
• 99.244.169.127

The worm may then attempt to send gathered information to one of the above IP addresses using a randomly named file location with the one of the following extensions:

• .htm
• .png

Next, the worm opens a back door, which may allow a remote attacker to perform the following actions on the compromised computer:

• Steal information
  
• End processes
• Update the worm
  
• Download files
  
• Send spam

The worm spreads by sending email containing links to copies of itself.

The email has the following characteristics:

Subject:
One of the following:

• Merry Christmas wishes just for you
• Merry Xmas!
• You've got a Merry Christmas greeting card
• Xmas card for you
• I made an Ecard for U!
• Merry Christmas e-card is waiting for you
• Merry Christmas 2009!
• It is amazing
• I’m in shock!
• Breaking news about our president-elect
  
• Awful news
• Amazing news about Inauguration
  
• Breaking news about Inauguration
  
• Haven’t you heard news?
• Important news about inauguration
  
• I hope that is not true!
• What is going on with our country?
• You will not believe in it!
• Me and You
• Together forever
• Deep in my heart
• Madly in love
• Here in my heart
• Can't forget you
  

Message Body:
One of the following:

[NAME] has created for you an e-card.
Here's your greeting card:
[URL]
Your eCard will be available for the next [TWO DIGITS] days

or

Obama is afraid of being a president [URL]
Faithfully yours,


Note: [URL] above denotes a URL on one of the following domains that hosts copies of the worm:

• [http://]itsfatherchristmas.com
• [http://]bestchristmascard.com
• [http://]whitewhitechristmas.com
• [http://]christmaslightsnow.com
• [http://]freechristmasworld.com
• [http://]youryearcard.com
• [http://]bestyearcard.com
• [http://]funnychristmasguide.com
• [http://]Greatobamaguide.com
• [http://]Greatobamaonline.com
• [http://]Superobamadirect.com
• [http://]Superobamaonline.com
• [http://]Bestbarack.com
• [http://]Bestbaracksite.com
• [http://]Bestobamadirect.com
• [http://]Greatobamaguide.com
• [http://]jobarack.com
• [http://]bestgoodnews.com
• [http://]goodnewsdigital.com
• [http://]goodnewsreview.com
• [http://]linkworldnews.com
• [http://]reportradio.com
• [http://]spacemynews.com
• [http://]wapcitynews.com
• [http://]worldnewsdot.com
• [http://]worldnewseye.com
• [http://]worldtracknews.com

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
• Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
• Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
• Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
• If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
• If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
• For further information on the terms used in this document, please refer to the Security Response glossary.

Summary