This new variant of W32/Mydoom is packed with ASPack.
The dropped SERVICES.EXE is the same binary
The behaviour is similar to W32/Mydoom.o@MM
and bears the following characteristics:
- mass-mailing worm constructing messages using its own SMTP engine
- harvests email addresses from the victim machine
- spoofs the From: address
- contains a peer to peer propagation routine
(spoofed From: header)
Do not assume that the sender address is an indication that the sender is infected. Additionally you may receive alert messages from a mail server that you are infected, which may not be the case.
The From: address may be spoofed with a harvested email address. Additionally, it may be constructed so as to appear as a bounce, using the following addresses:
The following display names are used in this case:
- "Automatic Email Delivery Software"
- "Bounced mail"
- "Mail Administrator"
- "Mail Delivery Subsystem"
- "Post Office"
- "Returned mail"
- "The Post Office"
The following subjects are used:
- delivery failed
- Message could not be delivered
- Mail System Error - Returned Mail
- Delivery reports about your e-mail
- Returned mail: see transcript for details
- Returned mail: Data format error
The virus constructs messages from pools of strings it carries in its body. For example:
The attachment may be an EXE file with one of the following extensions:
It may also be a copy of the worm within a ZIP file (may be doubly ZIPped). In this case the extension is:
The attachment may use the target email address name as the filename, in addition to the following:
The attachment may use a double extension, and there may be multiple spaces inserted between the file extensions to deceive users.
Email Address Harvesting
Email addresses are harvested from the following file types on the victim machine:
The virus queries
four search engines to harvest addresses from the results returned from such queries
The virus will also harvest email addresses from any Outlook window that is active on the victim machine.
The virus avoids emailing itself to target domains containing any of the following strings:
Peer to Peer Propagation
The virus is intended to copy itself to folders containing the following strings: