Threat Descriptions

Worm:W32/NetSky.Q

Classification

Category :

Malware

Type :

Email-Worm

Platform :

W32

Aliases :

NetSky.Q, W32/Netsky.Q, I-Worm.Netsky.r, W32/Netsky.Q@mm

Summary

The Netsky.Q variant was discovered on March 29th, 2004.This worm spreads in email using different exploits and social engineering. NetSky.Q performs a DDoS against several websites and makes the infected computers beep randomly.

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

System Infection

Upon execution the worm copies its dropper to the Windows Directory as 'SysMonXP.exe', which is added to the registry: 

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run] =

"SysMonXP" = "%WinDir%\SysMonXP.exe"

where %WinDir% represents Windows directory name.

The main DLL is placed to the same place with the filename 'firewallogger.txt' alongside with other temporary files used by the worm: 

'zipo0.txt'
'zipo1.txt'
'zipo2.txt'
'zipo3.txt'
'base64.tmp'
'zippedbase64.tmp'

The worm removes several registry values that belong to other worms.

Email Propagation

When collecting addresses NetSky.Q recursively searches through all hard drives and checks the content of files with the following extensions: 

.adb
.asp
.cfg
.cgi
.dbx
.dhtm
.doc
.eml
.htm
.html
.jsp
.mbx
.mdx
.mht
.mmf
.msg
.nch
.ods
.oft
.php
.pl
.ppt
.rtf
.sht
.shtm
.stm
.tbb
.txt
.uin
.vbs
.wab
.wsh
.xls
.xml

This variant of NetSky sends emails that look like error messages from mail servers.

Here's an example of what messages sent by Netsky.Q can look like:

The emails are composed from the following parts:

Subjects:

Delivery Error   Delivery Failure   Delivery   Mail Delivery failure   Mail Delivery System   Mail System   Delivery   Delivered Message   Error   Status   Failure   Failed   Unknown Exception   Delivery Failed   Deliver Mail   Server Error   Delivery Bot

Bodies:

Delivery Error
 Delivery Failure
 Delivery
 Mail Delivery failure
 Mail Delivery System
 Mail System
 Delivery
 Delivered Message
 Error
 Status
 Failure
 Failed
 Unknown Exception
 Delivery Failed
 Deliver Mail
 Server Error
 Delivery Bot

The attachment name is created from one of the following names: 

message  msg  mail  data

The file extension is either '.pif' or '.zip'. In case of ZIP files the filename inside the ZIP can be one of 

data.eml.scr  mail.eml.scr  msg.eml.scr  message.eml.scr

The purpose of large number of spaces between the extensions is to the hide the executable extension from the users' eyes, leaving them with the harmless looking '.eml' to open.

The email can contain different endings that attempt to start the attachment or make the user to do so.

  • A link with the format: www.<recipient domain>/inmail/<recipient username>/mread.php?sessionid-<random>
  • An exploit for MS01-020 (IFRAME) to execute the attachment automatically. More information on the vulnerability and patches are available from https://www.microsoft.com/technet/security/bulletin/MS01-020.mspx
  • Plain attachment with '.pif' or '.zip' extension

Payloads

Between 7th and 12th of April, 2004 NetSky.Q infected computers will perform a Distributed Denial-of-Service attack against the following sites: 

Delivery Error
 Delivery Failure
 Delivery
 Mail Delivery failure
 Mail Delivery System
 Mail System
 Delivery
 Delivered Message
 Error
 Status
 Failure
 Failed
 Unknown Exception
 Delivery Failed
 Deliver Mail
 Server Error
 Delivery Bot

On 30th of March, 2004 NetSky.Q will make the infected computer to beep randomly between 5AM and 11AM.