Another NetSky worm variant - NetSky.G was found on 4th of March 2004. This variant spreads itself in emails as an executable attachment.This worm contains another insulting message for the authors of Bagle and Mydoom worms and a proposal to meet in person in some location in the USA. The location name is encrypted.Like its previous variants NetSky.G tries to uninstall Bagle worm variants from an infected computer.
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.
Descriptions of all previous NetSky worm variants can be found here:
The worm's file is a PE executable file about 27 kilobytes long, packed with PE-Patch and TELock file compressors. The unpacked file's size is over 31 kilobytes.
On March 10th, 2004 the worm constantly beeps with PC speaker from 6:00 to 8:59. Below is the link to the WAV file with the sound that the worm makes: https://www.f-secure.com/v-pics/netsky_d.wav
NetSky.G worm doesn't copy its files to shared folders.
When run, the worm installs itself to system. It copies its file to Windows folder as AVGUARD.EXE and creates a startup key for this file in System Registry:
[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run] "Special Firewall Service" = "%windir%\avguard.exe -av service"
where %windir% represents Windows directory
The worm creates a mutex named "Netsky AV Guard" to avoid running more than one instance of itself.
NetSky.G worm has its own SMTP engine that it uses to send emails with infected attachments to all found email addresses. The worm uses different subjects, message body texts and attachment names in its emails.
The worm scans all available drives except CD-ROM drives for emails. It searches for email addresses in files with the following extensions:
.eml .txt .php .pl .htm .html .vbs .rtf .uin .asp .wab .doc .adb .tbb .dbx .sht .oft .msg .shtm .cgi .dhtm
The subject for infected messages is selected from the following list:
Re: Document Re: Re: Document Re: Re: Thanks! Re: Thanks! Re: Your document Re: Here is the document Re: Your picture Re: Re: Message Re: Hi Re: Hello Re: Re: Re: Your document Re: Here Re: Your music Re: Your software Re: Approved Re: Details Re: Excel file Re: Word file Re: My details Re: Your details Re: Your bill Re: Your text Re: Your archive Re: Your letter Re: Your product Re: Your website
The message body text for infected messages is selected from the following list:
Your document is attached. Here is the file. See the attached file for details. Please have a look at the attached file. Please read the attached file. Your file is attached.
The attachment name for infected messages is selected from the following list:
your_document.pif your_document.pif document.pif message_part2.pif your_document.pif document_full.pif your_picture.pif message_details.pif your_file.pif your_picture.pif document_4351.pif yours.pif mp3music.pif application.pif all_document.pif my_details.pif document_excel.pif document_word.pif my_details.pif your_details.pif your_bill.pif your_text.pif your_archive.pif your_letter.pif your_product.pif your_website.pif
The worm avoids sending emails to email addresses that contain any of the following substrings:
icrosoft antivi ymantec spam avp f-secur itdefender orman cafee aspersky f-pro orton fbi abuse messagelabs skynet andasoftwa freeav sophos antivir iruslis
The NetSky.G worm variant of the worm deletes the following Registry keys:
[HKCR\CLSID\{E6FB5E20-DE35-11CF-9C87-00AA005127ED}\InProcServer32] [HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\PINF] [HKLM\System\CurrentControlSet\Services\WksPatch] [HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices]
system. [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
KasperskyAv
Explorer
Taskmon
system.
msgsvr32
DELETE ME
service
Sentry
Windows Services Host [HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
KasperskyAv
Explorer
OLE
Windows Services Host
d3dupdate.exe
au.exe
sysmon.exe
rate.exe
gouday.exe
sate.exe
ssate.exe
srate.exe
NetSky.G worm removes Registry keys of several Bagle worm variants if it finds them on an infected computer. At least the last 8 keys listed above belong to earlier Bagle variants.