Worm:W32/NetSky.AF

Classification

Category :

Malware

Type :

Worm

Aliases :

NetSky.AF, WORM_NETSKY.AF, I-Worm.NetSky.b, W32/Netsky.ag@MM, W32.Netsky.AD@mm

Summary

NetSky.AF spreads itself in emails inside a ZIP archive or as an executable attachment. It also copies itself to shared folders of all available drives. This allows the worm to spread in peer-to-peer and local networks. It is related to NetSky.B.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

NetSky.AF arrives as email attachment. When run, it displays a message box with title "Fail" and message "File Corrupted replace this!!" and OK button. It then copies itself to %WinDir% directory under the name MsnMsgrs.exe and adds RUN key to ensure the worm is started after reboot.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run "MsnMsgr"

 %WinDir%\MsnMsgrs.exe -alev

%WinDir% represents WINDOWS directory.

NetSky.AF then searches local drives for email addresses. Files with following extensions are scanned for email addresses:

.SCS
.oft
.sht
.dbx
.tbb
.adb
.doc
.wab
.asp
.uin
.rtf
.vbs
.html
.htm
.pl
.php
.txt
.eml

If the worm finds folder with the 'sharing' or 'share' in its name it will copy itself there under the following names:

aninha gatinha!.zip.scr
barrio.scr
cafe!!.zip.scr
Canaval2004!.jpg.pif
Carnaval em Salvador!!.zip.scr
caspa.scr
celulares!!.zip.scr
clica ai logo meu.scr
comoserrico!.zip.scr
importante!!!!!.zip.scr
minhavida!.zip.exe
MulataDandoOcujpg.scr
multas.pif
paula!.scr
puteiros!!.scr
receitas de bolo!!.zip.scr
rede globo tv!.zip.scr
ResidentEvil2.zip.scr
rocha.scr
traficoemSP!.scr
vadias peladas!!.scr
vida!!.zip.scr
VivaNaBaia!.scr
vota!.zip.scr

NetSky.AF also creates ZIP files under %WinDir% with the following names

agua!.zip
aqui.zip
banco!.zip
bingos!.zip
carros!.zip
circular.zip
contas!!.zip
criancas!.zip
dinheiro!!.zip
docs.zip
email.zip
festa!!.zip
flipe.zip
grana!!.zip
impressao!!.zip
jogo!.zip
lantrocidade.zip
loterias.zip
lulao!.zip
revista.zip
sampa!!.zip
sorteado!!.zip
tetas.zip
vaca.zip
vadias!.zip
vips!.zip

If internet connection is available, NetSky.AF uses own SMTP engine to send out infected email messages.

The attached files are chosen from the list above. The sender email address is spoofed and will be one of the collected addresses. The subject is one of the following:

0123456789
AninhaPutinha +55operado6992292246
vaca
tetas
war3!
AIDS!
grana
banco!
revista
lulao!
imposto
jogo!
loterias
vips!
missao
vadias!
email
flipe
botao
sampa!!
contas!!
zerado
:(
criancas!
brasil!
lantrocidade
aqui
docs
festa!!
LINUSTOR
bingos!
agua!
:D
sorteado!!
grana!!
dinheiro!!
carros!
voce
:-)
???
circular
agradou
diga
robos!
impressao!!
massas!
pescaria por kilo
Sua saude esta bem?
morto
:)

And the message body will be one of the following

me veja peladinha
gostaria disso e voce???
algo a mais
falea verdade!!!
ganhe muita grana
campanhadafome
pq nao me liga??
sinto voce!!
grana
Lembra?
amor me liga
Hackers do Brasil
Medical Labs Exames!!!
meutelefone liga
ferias nos E.U.A
Surto :(
Vacina contra o HIV!!
sua conta bancaria zerada
olha que isso!!!
parabens!
te amo!
Policia SP
Sua Conta!!
Boleto Pague
veja o que tem no zip e me liga
receitas de bolo!!
acrdito que em voce!!!
promocao de viajens de fim de ano
tudo sobre voce sabe
Proposta de emprego!!
estou doente veja!!!
me diz o queacha?
retorna logo isso!!
arquivo zipado PGP???
voce passou :D!!!
ve ai logo ta
AMA!
AmaVoce
Abra rapido isso!!!!
reza de sao tome!!!!
veja detalhes!!!
encontro voce!
preenche ai ta bom
PizzaVeneza!