Wikileaks releases copies of FinFisher surveillance software

https://wikileaks.org/spyfiles4/index.html

by dpina • 12 years ago

184 32 12 years ago

wikileaks.org

Strom• 12 years ago

See yesterday's discussion https://news.ycombinator.com/item?id=8317358

markvdb• 12 years ago

I wonder why they use MD5 hashes and not something more collision attack resistant.

arturventura• 12 years ago

Because it would be very hard to find a collision of a file that behaves exactly like a ZipFile.

To make a collision work, you would need to inject the payload into the program, and find a specific blob to put into the zip file, that once compressed and hashed would cause a collision. This isn't computationally efficient.

hrjet• 12 years ago

I am not familiar with zip file format, but if zip files allow comments or other meta-data (in uncompressed form) then it is an easier path. I suspect even file-names could be an opportunity.

tlrobinson• 12 years ago

This is the type of assumption that can get you in trouble. Zip files can contain uncompressed files.

epimenov• 12 years ago

That's not true. What people do is take a zip file and then append files to the end till you get desired md5. It would behave like a zip file.

See http://www.mscs.dal.ca/~selinger/md5collision/

xwintermutex• 12 years ago

One can prepend any data to a zip file and it will still be valid.

un1xl0ser• 12 years ago

Collision resistance is more interesting when hashes are used in cryptographic protocols and large amounts of data can be captured, seen and analyzed.

I can't think of a purpose where a collision of a non-malicious sample with a malicious file can be used by an attacker (let alone the same attacker). In addition, there are lots of historical threat data (tactical intelligence) that is based on md5sums. Newer tools support newer checksums, but will more than likely just increase the types of checksums supported, and not deprecate them.

Checksums are less and less useful when the malware can be configured, recompiled and re-assembled for a particular target. There are some good discussions on HN more fuzzy detection techniques that can't be evaded by changing inert parts of the payload, but that is orthogonal to using stronger checksums. Indicator of Compromise data including md5sums can be useful for general security, but because a determined attacker will mutate the files it is better suited to more commodity malware.

Someone12345• 12 years ago

Collisions aren't a major risk with MD5 when you also give someone the file size (even approximate).

Finding a collision in MD5 is costly, finding a collision in MD5 which is within -+10% of the actual size is extremely costly (technically possible, but maybe not in your lifetime).

As to the other reply "because it is zip something something" I disagree. Zip is an extremely good format for crafting fake files which match a checksum. Really any format which can take arbitrary metadata (which is MOST) is pretty easy.

I suspect the reason they use MD5 is because everywhere supports it and it is "good enough," particularly with file size. Plus the person downloading them knows the files are malware, so what could the security services do, inject an even more malware-malware that they then expect the user to run?! Seems dumb. You're likely more at risk from day to day applications installers which aren't digitally signed.

EthanHeilman5• 12 years ago

Finding a collision in MD5 is costly, finding a collision in MD5 which is within -+10% of the actual size is extremely costly (technically possible, but maybe not in your lifetime).

MD5 collisions with 10% of the size of the file can be found in seconds on a old laptop computer. I've done it, we assign it as HW in class.

Read this http://www.mathstat.dal.ca/~selinger/md5collision/

Notice that the two colliding exe are exactly the same file size. These attacks have only gotten better.

Zip is an extremely good format for crafting fake files which match a checksum. Really any format which can take arbitrary metadata (which is MOST) is pretty easy.

The example I gave uses windows and linux executables. No zip files in sight. These attacks are from 2009.

userbinator• 12 years ago

Finding a collision in MD5 is costly

Not at all; look up "md5coll" and "fastcoll", released nearly 10 years ago, could generate a pair of colliding blocks in under an hour. Testing them now on my machine (which is already a few years old) it generated them in under a second(!)

This has been used to create executables that behave differently but that's because they can inspect themselves; on the other hand I think generating two .zip files with the same hash but different (valid) contents would be rather more difficult, but it's probably still quite feasible today.

emmelaich• 12 years ago

That's a point I've always wondered about. Given that most (all?) md5 collisions consist of appending or prepending data, how much more difficult would it be if you encode the size as well.

Surely the difficulty is much more. And then add the fact that it has to be semantically/syntactically similar enough to fool whatever ingests it...

EthanHeilman5• 12 years ago

They should definitely not being using MD5 for anything. Even if the people in this thread saying that finding MD5 collisions is hard were correct, and they aren't, why take the risk? The performance benefits aren't large for MD5 over competing hash functions that don't have know systemic weaknesses and MD5 attacks will only get better.

Use SHA256, SHA-3 or MD6 (I like MD6, others may disagree. Disclaimer I worked on proving the differential resistance of MD6).

tptacek• 12 years ago

MD6 is an idiosyncratic recommendation.

andy_ppp• 12 years ago

So, anyone planning to install it?

DennisP• 12 years ago

Now that it's publicly released, it seems like a good idea to install it just to make sure your own systems aren't vulnerable to it.

q3k• 12 years ago

So, how long until finds RCE bugs in the Proxy, Relay and Master? There is possibly quite a bit of these to be found via Shodan...

billyboar• 12 years ago

Too shame that they're using so much of money, which is basically tax money of Mongolian people, on surveillance tool when Mongolians living their like hell. shame on them.

JetSpiegel2• 12 years ago

That ggi file is a self-extracting bash script.

    #!/bin/bash
    echo ""
    echo " FInstaller 1.0"
    echo "-----------------------"
 
    export TMPDIR=`mktemp -d /tmp/selfextract.XXXXXX`
 
    ARCHIVE=`awk '/^__ARCHIVE_BELOW__/ {print NR + 1; exit 0; }' $0`
 
    echo ""
    echo "Extracting Installation Files..."
    echo ""
 
    tail -n+$ARCHIVE $0 | tar xzv -C $TMPDIR
 
    echo ""
    echo "Launching Installer..."
    echo ""
 
    CDIR=`pwd`
    echo CDIR
    echo $CDIR
    echo TMPDIR
    echo $TMPDIR
    cd $TMPDIR
    ./installer
 
    cd $CDIR
    rm -rf $TMPDIR
 
    exit 0
 
    __ARCHIVE_BELOW

And then the data.

JetSpiegel2• 12 years ago

The installer is an even messier piece of code.

    #!/bin/bash
 
    TOP_INSTALL_DIR=/
 
    echo "Stopping FFRelay"
 
    monit stop ffrelay
    sleep 3
    killall -9 -q ffrelay
    echo "Extracting Software Files..."
    tar --directory $TOP_INSTALL_DIR  -xvf ./*relay*.tar
 
    echo ""
    echo "Running Post-Installation Steps..."
 
    SECONDS=1
    MAX_SECONDS=10
 
    while [ "$SECONDS" -lt "$MAX_SECONDS" ]
      do
           if [ -e "/var/run/ffrelay.pid" ]; then
               sleep 1
           else
               SECONDS=$MAX_SECONDS
           fi
      done
 
 
    echo "Starting FFRelay"
 
    monit start ffrelay
 
    echo ""
    echo "FFRelay Installer done."
    echo ""

They should have just used a .deb

D4AHNGM• 12 years ago

Interestingly, Sophos on OS X immediately identifies the .zip as Malware/Generic-Spyware and blocks access to it:

finspy_master.zip: Permission denied

Wikileaks releases copies of FinFisher surveillance software

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