Name
Conficker
Detection names
Sophos Mal/Conficker-A, W32/Confick-A, W32/Confick-D
Kaspersky Net-Worm.Win32.Kido.gen, Net-Worm.Win32.Kido.ih, Net-Worm.Win32.Kido.bj
Avira Worm/Conficker.AH, Worm/Conficker.Z.02
McAfee W32/Conficker.Worm.gen.a, W32/Conficker.worm
Trend Micro WORM_DOWNAD.A, WORM_DOWNAD.AD
Microsoft Worm:Win32/Conficker.gen!A, Worm:Win32/Conficker.B
Symantec W32.Downadup, W32.Downadup.B
Affected OS or software
Microsoft Windows
Basic description
Conficker is a worm for the Windows platform. It first appeared in late 2008 and is now the most commonly seen malware worldwide. Conficker’s success is due to the multiple methods it uses to spread, exploiting an operating system vulnerability (now patched), weak passwords and removable storage devices.
Technical detail
Conficker is a worm for the Windows platform.
Conficker may spread through Windows file shares protected with weak passwords (or to which a logged on domain administrator has access), by copying itself to removable storage devices and by exploiting the MS08-067 Windows Server service vulnerability.
Conficker will attempt to copy itself to the following location:
<System>\<random filename>
(e.g., C:\Windows\system32\zdtnx.g or C:\Windows\system32\kdcktv.dll)
This file is set up to run as a service, also using a random name, when Windows starts. Conficker also modifies permissions on the service registry entries so that they are not visible to the user.
The registry entries added by Conficker are under:
HKLM\SYSTEM\CurrentControlSet\Services\<random service name>
The random service name will also be added to the list of services referenced by:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost\netsvcs
When spreading to removable media Conficker attempts to create the following hidden files:
<Removable Drive Root>\autorun.inf
<Removable Drive Root>\RECYCLER\S-x-x-x-xxx-xxx-xxx-x\<Random Letters>.dll (where x represents a random digit)
Once installed Conficker will patch the netapi32.dll function NetpwPathCanonicalize in memory to disable the MS08-067 exploit that it uses to spread. Later versions of Conficker include a backdoor in this patch that allows the worm to extract URLs from incoming MS08-067 shellcode and download and execute files from them directly. This allows Conficker to receive update information from other infected computers.
Later variants of Conficker will create a named pipe at the following location:
\\.\pipe\System_<Computer name>7
Conficker will listen for URLs on this named pipe and will attempt to download and possibly execute files downloaded from such URLs.
Each day Conficker generates a set of up to 50,000 domain names and attempts to contact a random selection of them. Details of this mechanism are described in the Conficker Technical Analysis paper.
Once active the worm will attempt to determine the public IP address of the infected computer by visiting one or more of the following websites:
www.whatsmyipaddress.com
www.getmyip.org
www.whatismyip.org
checkip.dyndns.org
The worm will also access one of more of the following sites:
www.myspace.com
www.ebay.com
www.msn.com
www.cnn.com
www.aol.com
When spreading to other computers on the network Conficker will attempt to access the ADMIN$ share using the following passwords:
99999999
9999999
999999
99999
9999
999
99
9
88888888
8888888
888888
88888
8888
888
88
8
77777777
7777777
777777
77777
7777
777
77
7
66666666
6666666
666666
66666
6666
666
66
6
55555555
5555555
555555
55555
5555
555
55
5
44444444
4444444
444444
44444
4444
444
44
4
33333333
3333333
333333
33333
3333
333
33
3
22222222
2222222
222222
22222
2222
222
22
2
11111111
1111111
111111
11111
1111
111
11
1
00000000
0000000
00000
0000
000
00
0987654321
987654321
87654321
7654321 |
654321
54321
4321
321
21
12
fuck
zzzzz
zzzz
zzz
xxxxx
xxxx
xxx
qqqqq
qqqq
qqq
aaaaa
aaaa
aaa
sql
file
web
foo
job
home
work
intranet
controller
killer
games
private
market
coffee
cookie
forever
freedom
student
account
academia
files
windows
monitor
unknown
anything
letitbe
letmein
domain
access
money
campus
explorer
exchange
customer
cluster
nobody
codeword
codename
changeme
desktop
security
secure
public
system
shadow
office
supervisor
superuser
share
super
secret
server
computer
owner
backup
database
lotus
oracle
business
manager
temporary
ihavenopass
nothing |
nopassword
nopass
Internet
internet
example
sample
love123
boss123
work123
home123
mypc123
temp123
test123
qwe123
abc123
pw123
root123
pass123
pass12
pass1
admin123
admin12
admin1
password123
password12
password1
default
foobar
foofoo
temptemp
temp
testtest
test
rootroot
root
adminadmin
mypassword
mypass
pass
Login
login
Password
password
passwd
zxcvbn
zxcvb
zxccxz
zxcxz
qazwsxedc
qazwsx
q1w2e3
qweasdzxc
asdfgh
asdzxc
asddsa
asdsa
qweasd
qwerty
qweewq
qwewq
nimda
administrator
Admin
admin
a1b2c3
1q2w3e
1234qwer
1234abcd
123asd
123qwe
123abc
123321
12321
123123
1234567890
123456789
12345678
1234567
123456
12345
1234
123 |
Conficker attempts to prevent the infected computer from obtaining security information and updates by blocking access to websites that have any the following strings in their domain name:
cert.
sans.
bit9.
vet.
avg.
avp.
ca.
nai.
windowsupdate
wilderssecurity
threatexpert
castlecops
spamhaus
cpsecure
arcabit
emsisoft
sunbelt
securecomputing
rising
prevx |
pctools
norman
k7computing
ikarus
hauri
hacksoft
gdata
fortinet
ewido
clamav
comodo
quickheal
avira
avast
esafe
ahnlab
centralcommand
drweb
grisoft
eset |
nod32
f-prot
jotti
kaspersky
f-secure
computerassociates
networkassociates
etrust
panda
sophos
trendmicro
mcafee
norton
symantec
microsoft
defender
rootkit
malware
spyware
virus |
Related links
A technical analysis of Conficker (PDF) is available.
Conficker Removal Tool: How to install and run the tool
The Conficker worm three years and counting
Sophos Anti-Virus: Tracking and finding Conficker infections
Defending against the threat
Conficker is now over 3 years old and is detected by all reputable antivirus software. Common security measures such as strong passwords and avoiding using administrator level accounts when they are not necessary will limit the spread of a Conficker infection. Apply the MS08-067 security update from Microsoft.
Patches
Microsoft has patched the Windows Server service vulnerability exploited by Conficker. See the security bulletin here.
Applying this patch does not completely prevent the spread of Conficker because the worm also uses other methods of propagation.
Sophos technologies
Sophos Anti-Virus detects and removes Conficker. Sophos also provides a standalone Conficker removal tool, further information about this tool can be found in the Sophos Knowledgebase.
Sophos Endpoint 10 includes patch assessment technology to alert you when endpoints are missing important security patches.