[Mimedefang] SoBig.E slipping through

[Tony L. Cratz]

> 	mimedefang.pl -structure < the_message
> 
> to see how mimedefang parses the MIME structure.
> 
> When I did it with the sample you sent, I got this:
> 
> non-leaf: type=multipart/mixed; fname=; disp=inline
>     leaf: type=text/plain; fname=; disp=inline
>     leaf: type=application/x-zip-compressed; fname=your_details.zi;
> disp=attachment

	I also have been having a similar problem in that this virus
	Keeps getting passed mimedefang/clamd.

	When I did the above I got:

mimedefang.pl -structure < sobig.virus
non-leaf: type=multipart/mixed; fname=; disp=inline
    leaf: type=text/plain; fname=; disp=inline
    leaf: type=application/x-zip-compressed; fname=your_details.zip;
disp=inline

	If I run clamdscan or clamscan on the file, it tells me that
	it is a virus. But it passes right through mimedefang-2.34/clamd

	Without any problem.

	Below is a copy of my clamav.conf file. And my mimedefang-filter
	is very close to what was shipped in 2.34.

	What am I doing wrong?

	
Tony

------------------------------------------------------------------------
##
## Example config file for the Clam AV daemon
## Please read the clamav.conf(5) manual before editing this file.
##
 

# Comment or remove the line below.
#Example

# Uncomment this option to enable logging.
# LogFile must be writable for the user running the daemon.
# Full path is required.
LogFile /tmp/clamd.log

# By default the log file is locked for writing - the lock protects
against
# running clamd multiple times (if want to run another clamd, please
# copy the configuration file, change the LogFile variable, and run
# the daemon with --config-file option). That's why you shouldn't
uncomment
# this option.
#LogFileUnlock

# Maximal size of the log file. Default is 1 Mb.
# Value of 0 disables the limit.
# You may use 'M' or 'm' for megabytes (1M = 1m = 1048576 bytes)
# and 'K' or 'k' for kilobytes (1K = 1k = 1024 bytes). To specify the
size
# in bytes just don't use modifiers.
#LogFileMaxSize 2M

# Log time with an each message.
LogTime

# Use system logger (can work together with LogFile).
LogSyslog

# Enable verbose logging.
#LogVerbose

# This option allows you to save the process identifier of the listening
# daemon (main thread).
PidFile /var/run/clam/clamd.pid

# Path to a directory containing .db files.
# Default is the hardcoded directory (mostly /usr/local/share/clamav,
# it depends on installation options).
DataDirectory /opt/share/clamav
 
# The daemon works in local or network mode. Currently the local mode is
# recommended for security reasons.

# Path to the local socket. The daemon doesn't change the mode of the
# created file (portability reasons). You may want to create it in a
directory
# which is only accessible for a user running daemon.
#LocalSocket /tmp/clamd
LocalSocket /var/spool/MIMEDefang/clamd.sock

# TCP port address.
#TCPSocket 3310

# Maximum length the queue of pending connections may grow to.
# Default is 15.
#MaxConnectionQueueLength 30

# Maximal number of a threads running at the same time.
# Default is 5, and it should be sufficient for a typical workstation.
# You may need to increase threads number for a server machine.
#MaxThreads 10

# Thread (scanner - single task) will be stopped after this time
(seconds).
# Default is 180. Value of 0 disables the timeout. SECURITY HINT:
Increase the
# timeout instead of disabling it.
#ThreadTimeout 500

# Maximal depth the directories are scanned at.
MaxDirectoryRecursion 15

# Follow a directory symlinks.
# SECURITY HINT: You should have enabled directory recursion limit to
# avoid potential problems.
FollowDirectorySymlinks

# Follow regular file symlinks.
FollowFileSymlinks

# Do internal checks (eg. check the integrity of the database
structures)
# By default clamd checks itself every 3600 seconds (1 hour).
#SelfCheck 600

# Run as selected user (clamd must be started by root).
# By default it doesn't drop privileges.
User defang

# Don't fork into background. Useful in debugging.
#Foreground

# Use ScannerDaemon's output format ("FOUND: virname" instead of
ClamAV's
# "file: virname FOUND"). clamdscan will refuse to work if this option
is
# enabled.
#ScannerDaemonOutputFormat

##
## Mail support
##

# Uncomment this option if you are planning to scan mail files.
ScanMail

##
## Archive support
##


# Comment this line to disable scanning of the archives.
ScanArchive

# Options below protect your system against Denial of Service attacks
# with archive bombs.

# Files in archives larger than this limit won't be scanned.
# Value of 0 disables the limit.
# WARNING: Due to the unrarlib implementation, whole files (one by one)
in RAR
#          archives are decompressed to the memory. That's why never
disable
#          this limit (but you may increase it of course!)
ArchiveMaxFileSize 15M

# Archives are scanned recursively - e.g. if Zip archive contains RAR
file,
# the RAR file will be decompressed, too (but only if recursion limit is
set
# at least to 1). With this option you may set the recursion level.
# Value of 0 disables the limit.
ArchiveMaxRecursion 5

# Number of files to be scanned within archive.
# Value of 0 disables the limit.
ArchiveMaxFiles 1500

# Use slower decompression algorithm which uses less memory. This option

# affects bzip2 decompressor only.
#ArchiveLimitMemoryUsage

##
## Clamuko settings
## WARNING: This is experimental software. It is very likely it will
hang
##          up your system !!!
##

# Enable Clamuko. Dazuko (/dev/dazuko) must be configured and running.
#ClamukoScanOnLine

# Set access mask for Clamuko.
#ClamukoScanOnOpen
#ClamukoScanOnClose
#ClamukoScanOnExec

# Set the include paths (all files in them will be scanned). You can
have
# multiple ClamukoIncludePath options, but each directory must be added
# in a seperate option. All subdirectories are scanned, too.
#ClamukoIncludePath /home
#ClamukoIncludePath /students

# Set the exclude paths. All subdirectories are also excluded.
#ClamukoExcludePath /home/guru

# Limit the file size to be scanned (probably you don't want to scan
your movie
# files ;))
# Value of 0 disables the limit. 1 Mb should be fine.
#ClamukoMaxFileSize 1M

# Enable archive support. It uses the limits from clamd section.
# (This option doesn't depend on ScanArchive, you can have archive
support
# in clamd disabled).
#ClamukoScanArchive

StreamSaveToDisk
StreamMaxLength 15M