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FileZilla Has an Evil Twin That Steals FTP Logins
Nerval's Lobster writes "On the same day the world discovered Western intelligence agencies were siphoning user information from Angry Birds and other popular smartphone apps, a leading antivirus developer revealed hackers are doing the same thing with one of the most popular open-source applications on the Internet. Maliciously modified versions of the popular FTP application FileZilla look and act just like the real thing, but include extra code that steals the login data typed in by users and sends it to an unauthorized server using the same FTP operation launched by the user without going through a firewall that might spot what it's doing, according to an alert posted this afternoon by antivirus developer Avast Software. The malicious version is fully functional, uses the same graphical interface and component file names as the original, and masks itself further by avoiding any suspicious entries in the system registry, overt attempts to communicate with outside servers or other changes, according to the Jan. 27 alert from Avast. The most obvious differences are that the poisoned version of filezilla.exe is 6.8MB smaller than the real thing and there are two DLL libraries included in the fake that are not present in the original. They are labeled ibgcc_s_dw2-1.dll and libstdc++-6.dll, according to Avast. The official version's Nullsoft installer is v2.45-Unicode; the evil twin uses v2.46.3-Unicode. Automatic updates also fail on the poisoned version 'which is most likely a protection to prevent overwriting of the malware binaries,' Avast added."
Mostly because these dll's are present in projects compiled with MingW.
From TFA
Stolen data is sent to the IP 144.76.120.243 that belongs [to a] server hosted in Germany.
"We found 3 domains that link to same IP:
go-upload.ru created 2012.09.23
aliserv2013.ru created 2013.09.09
ngusto-uro.ru created 2013.09.19
Unfortunately, domains are registered through the infamous Russian domain registrar Naunet.ru, which is associated with malware and spam activities. This registrar hides client contact info and ignores requests to suspend illegal domains.
No need to be condescending. I use FOSS all the time. Yet, AFAIK, there is no such mechanism that lets a developer introduce security fingerprints which "tag" a critical section of code, and which the compiler adds to the binaries, in such a way that after compiling source locally, you can check critical parts of your binaries on compliance with the "official" fingerprints. Or am I mistaken ?
There is no mechanism in most compilers/linkers that allows you to recreate the exact same executable that someone else built, byte by byte. You would need a compiler to be hundred percent deterministic. I could imagine some optimisation algorithms working better with some randomisation, so that wouldn't be possible. a+b could sometimes translate to "load a, add b" and sometimes "load b, add a". Things like the __FILE__ macro in C or C++ include the full path of the file, which is different on your machine than on mine. And of course you'd need the exact same build environment. Exact same version of every library that is used.
The question is really do you have SSD. It only takes a few days to build gentoo on some architecture which actually benefits from it, like a K6... with a laptop drive. On a modern machine with a SSD you ought to be able to knock it out in actually quite reasonable time.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
If FileZilla is only given access to the FTP port then it should block this behavior, correct?
What "FTP" port? Every FTP transfer requires a control connection and a data connection --- the data connection is established based on a procedure that depends on transfer mode -- there is standard mode, or passive mode (for firewall traversal).
In either case, the destination port number is not a specific FTP port, but a port number dynamically allocated by the server and presented to the client, or vice-versa
In Passive mode, to establish the data connection, the FTP client must open a connection back to the server ON ANY PORT specified by the server, sourced from its ftp-data port.
In Active mode, the client must select an ephemeral port from the 32768 to 65535 range, send it over the control connection, and accept a TCP connection from the server.
it wouldn't surprise me that if it were SourceForge's own "custom downloader" that's the one pushing the altered versions with login stealing functionality... it's been pushing adware and other crap too and FileZilla especially has been hit by this. Here's a short selection of complaints from the FileZilla forums:
https://forum.filezilla-project.org/viewtopic.php?f=2&t=30240
(this one has screenshots documenting the EXE installer hijacking done by SourceForge)
or this one: https://forum.filezilla-project.org/viewtopic.php?f=1&t=31127
and more... https://forum.filezilla-project.org/search.php?keywords=sourceforge+adware
Hi Folks,
SourceForge is aware of the malformed FileZilla FTP and are no way associated with or responsible for this malicious program posing as FileZilla.
The FileZilla installer on SourceForge is a stub that encapsulates the actual FileZilla installer to ensure the original FileZilla software is delivered. All offers that are presented when downloading FileZilla are optional and go through a rigorous verification and strict compliance process to make sure they are not malicious and virus free. No personally identifiable information is ever collected.
Best regards,
The SourceForge Community Team