I-Worm.Atak.a

Classification

Category :

Malware

Type :

Worm

Aliases :

I-Worm.Atak.a

Summary

A new simple massmailer was found on Monday 12th of July. It will attempt to spread on emails with an empty subject or one such as "Read the Result!", "Important Data!". It tries to disguise the original attachment extension by adding a large number of spaces after the beginning of the filename.

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

The worm will create a mutex named "SloperMtx" to avoid running more than once simultaneously.

It will copy itself to:

%SysDir%\hint.exe
 

Where %SysDir% is the local Windows System folder. First the worm attempts to create the file and then deletes it, finally copying itself to such location.

It will add an entry to the win.ini file using the Windows API call WritePrivateProfileStringA from the Kernel32.dll. The entry will have the form:

[windows]
load="%SysDir%\hint.exe"
 

Which will make Windows execute the worm on startup.

Afterwards it attempts to detect whether a debugger is loaded, aiming at avoiding being inspected by advanced users. It does so by calling the function IsDebuggerPresent from Kernel32.dll. The worm loads such DLL function itself, by means of Window's API LoadLiraryA.

Another trivial attempt of difficulting the analysis is when checking for Internet connection availability. It does so by loading a DLL, namely "wininet.dll", composing its name from parts "wini", "net." and "dll" at runtime. This a very basic and old "technique". Once it loads the DLL it will call its function, InternetGetConnectedState, to determine whether an Internet connection is available. If it's not so, it will wait, hoping the infected computer eventually goes online.

The following string is contained within the worm's body:

-={ 4tt4(k 4g4!n$t N3tSky, B34gl3, MyD00m, L0vG4t3, N4ch!, Bl4st3r }=-

Email spreading

The messages will have any of the following subjects, or no subject at all:

Read the Result!
Important Data!
 

The attachment will have a random name and extension ".gif" or ".jpg" followed by white spaces and finally ending with ".exe" or ".zip".

The worm will collect email address from files with extensions:

.wab
.adb
.tbb
.html
.xml
.cfg
.vbs
.msg
.dbx
.uin
.jsp
.asp
.cgi
.php
.sht
.mht
.ods
.log
.htm
.mbx
.nch
.eml
.txt
 

The worm has its own SMTP engine which will use to deliver the infected emails.