Email-Worm:W32/Mimail.L

Classification

Category :

Malware

Type :

Email-Worm

Aliases :

Mimail.L, W32/Mimail.m@mm, I-Worm.Mimail.l, I-Worm.Mimail.gen

Summary

Mimail.L worm was found on 1st of December, 2003. It is a variant of the Mimail worm family.

This worm sends messages which pretend to be very personal and contain pictures. The attached file is a ZIP that contains the worm.

The other type of message it sends will look like the recipients credit card would be billed for buying child porn, possibly scaring and confusing the recipients.

Removal

Manual disinfection of an Mimail.L infected computer consists of the following steps:

1, Remove the registry value

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run\France] 			

2, Restart the computer

3, Delete '%WinDir%\svchost.exe' (where %WinDir% is the Windows Directory, typically c:\windows\ or c:\winnt).

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 spreads in UPX packed form. The unpacked worm body is 24608 bytes in size and was written in C language.

Email Spreading

The virus sends two types of messages. One of them is sent with an infected attachment with the following text:

Hi Greg its Wendy.   I was shocked, when I found out that it wasn't you but your  twin brother!!!  That's amazing, you're as like as two  peas. No one in bed is better than you Greg. I remember, I  remember everything very well, that promised you to tell  how it was, I'll give you a call today after 9.        I'm so thankful to you, for acquainted me to your brother.  I think we can do i t on the next Saturday all three  together? What do you think? O yes, as you wanted I've made  a few pictures check them out in archive, I hope they will  excite you, and you will dream of our new meeting...  Wendy.  Attachment: wendy.zip 			  

The other message when sent by the virus does not contain any attachment but the worm has reportedly been seeded with the following text and an attachment called 'test.exe':

Hi Greg its Wendy.
 I was shocked, when I found out that it wasn't you but your
twin brother!!!
That's amazing, you're as like as two
peas. No one in bed is better than you Greg. I remember, I
remember everything very well, that promised you to tell
how it was, I'll give you a call today after 9.
I'm so thankful to you, for acquainted me to your brother.
I think we can do i t on the next Saturday all three
together? What do you think? O yes, as you wanted I've made
a few pictures check them out in archive, I hope they will
excite you, and you will dream of our new meeting...
Wendy.
Attachment: wendy.zip 			

This message is meant to scare and confuse the recipient and probably to hurt the reputation of the organizations mentioned in the mail.

The worm collects email addresses from files on the infected computer. It recursively searches through the user's document folders and looks into all the files whose extension is not on the following list:

Hi Greg its Wendy.
 I was shocked, when I found out that it wasn't you but your
twin brother!!!
That's amazing, you're as like as two
peas. No one in bed is better than you Greg. I remember, I
remember everything very well, that promised you to tell
how it was, I'll give you a call today after 9.
I'm so thankful to you, for acquainted me to your brother.
I think we can do i t on the next Saturday all three
together? What do you think? O yes, as you wanted I've made
a few pictures check them out in archive, I hope they will
excite you, and you will dream of our new meeting...
Wendy.
Attachment: wendy.zip 			

Using its own SMTP engine it sends emails with the malicious attachment. To find the SMTP server of the target email address the worm does an MX lookup using a predefined public DNS server.

System Infection

When started, Mimail.L first copies itself to the Windows Directory as 'svchost.exe'. This copy is added to the registry as

Hi Greg its Wendy.
 I was shocked, when I found out that it wasn't you but your
twin brother!!!
That's amazing, you're as like as two
peas. No one in bed is better than you Greg. I remember, I
remember everything very well, that promised you to tell
how it was, I'll give you a call today after 9.
I'm so thankful to you, for acquainted me to your brother.
I think we can do i t on the next Saturday all three
together? What do you think? O yes, as you wanted I've made
a few pictures check them out in archive, I hope they will
excite you, and you will dream of our new meeting...
Wendy.
Attachment: wendy.zip 			

to make sure the worm is started when Windows starts.

The worm creates several temporary files in the Windows directory:

Hi Greg its Wendy.
 I was shocked, when I found out that it wasn't you but your
twin brother!!!
That's amazing, you're as like as two
peas. No one in bed is better than you Greg. I remember, I
remember everything very well, that promised you to tell
how it was, I'll give you a call today after 9.
I'm so thankful to you, for acquainted me to your brother.
I think we can do i t on the next Saturday all three
together? What do you think? O yes, as you wanted I've made
a few pictures check them out in archive, I hope they will
excite you, and you will dream of our new meeting...
Wendy.
Attachment: wendy.zip 			

Payload

Computers infected with Mimail.L perform Distributed Denial-of-Service attacks on the following sites:

Hi Greg its Wendy.
 I was shocked, when I found out that it wasn't you but your
twin brother!!!
That's amazing, you're as like as two
peas. No one in bed is better than you Greg. I remember, I
remember everything very well, that promised you to tell
how it was, I'll give you a call today after 9.
I'm so thankful to you, for acquainted me to your brother.
I think we can do i t on the next Saturday all three
together? What do you think? O yes, as you wanted I've made
a few pictures check them out in archive, I hope they will
excite you, and you will dream of our new meeting...
Wendy.
Attachment: wendy.zip 			

Mimail.L also contains this text which is never shown:

Hi Greg its Wendy.
 I was shocked, when I found out that it wasn't you but your
twin brother!!!
That's amazing, you're as like as two
peas. No one in bed is better than you Greg. I remember, I
remember everything very well, that promised you to tell
how it was, I'll give you a call today after 9.
I'm so thankful to you, for acquainted me to your brother.
I think we can do i t on the next Saturday all three
together? What do you think? O yes, as you wanted I've made
a few pictures check them out in archive, I hope they will
excite you, and you will dream of our new meeting...
Wendy.
Attachment: wendy.zip