Category Archives: Malware forensics

A relative got hacked for scamming activities

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One of my relative got hacked.

After a phone conversation with him, I realized that his computer was hacked a few days before. He told me that he saw the mouse moving by itself, but what happened then was not clear to him. Anyway, he did not feel the urge to call me immediately. Needless to say that his knowledge on computers is low.
I immediately started to investigate.

How the computer was hacked

The computer is running Ubuntu . I suspected a vulnerability, but I soon realized that it was much simpler than that: by mistake, a VNC session was left opened!

x11vnc with no authentication and no logging… Damned!

What the attacker did

What he tried first was to create a user to maintain access. But the scammer was probably low tech and soon abandonned.

Here is his sequence in the shell history:

261 adduser -u 0 -o -g 0 -G 0,1,2,3,4,6,10 -M xxxcx
262 useradd -d /home/xxxcx -m nokia00
263 passwd xxxcx

Command #261 failed, because of unproper syntax. I guess he meant useradd, as adduser on Debian/Ubuntu has totally different options. Note that what he was trying to do is create a new root user named xxxcx (with no home directory).

He probably did not realize his mistake, but yet tried this time useradd with fewer options in command #262. This time, he would create the home directory and name the user nokia00… Why not. Alas, the command can’t work as a standard user!

Then, command #263: he tried to change the current password, but again he failed as it is required to know it before updating it…

And that’s it. Pretty lame, isn’t it? He got quickly discouraged and started to use exclusively Firefox.

On-line shopping

With support of forensicswiki.org, I dumped the full Firefox profile on my computer and started to analyze it with the Sqlite Manager extension.

Sorry but I will be hiding private info and sensitive data that could be used for a legal action.

I got most info from the files cookies.sqlite and places.sqlite.

cookies.sqlite: a lot of info: email and billing info used by the attacker

cookies.sqlite: a lot of info: email and billing info used by the attacker

places

places.sqlite: attacker’s browsing history, with interesting purchase references in GET parameters

The guy didn’t loose time, he knew precisely what he wanted and what to do.

  1. He first visited two websites to localize the computer: ip2location.com and ip-tracker.org. You may think that it is a strange first move, but I will come back on that later as I have a theory.
  2. Now that he knew in what country he was (country XXX), he started to do online shopping.

It is interesting that his online shopping was all linked to web hosting:

  • templates from dreamtemplates.com
  • a .net domain name (with however part of the prefix being localized accordingly to the country suffix).
  • hosting at netfirms.com and mg1host.com

Note that the criminal used a online payment platform that I never heard about before: 2checkout.com aka 2co.com.

Unfortunately, when I investigated, all cookies were expired so I could not connect to the criminal’s account.

Yet, it still had some valuable info. The most interesting info I found was from a cookie from dreamtemplates.com. I got all the billing info used by the attacker:

  • attacker’s gmail address (probably compromised or anonymous)
  • Name and address for the billing, that sounded real…

Also, GET parameters in URLs were very interesting.

In some of them, you can guess the amount of the purchase he did. He for sure bought stuff for at least a total of 500$. But it is without counting the stuff that I cannot guess from URLs, so it is probably sensibly much more in reality.

But, even better, some had order ids. Hey, wait! Let’s have a look on the 2co website:

2co order review = order number + email

2co order review = order number + email

Hmmm… we have the email address and the order number… bingo!

order

Now, we have at least all info of the credit card owner, certainly the biggest victim in this mess.

Conclusion

That’s it for now. We are still in the process of transmitting the info to the police and alerting the victim.

Here are a few thoughts by the way:

  • Logging, always logging! It is a pity that we know literally nothing about the scammer source ip address. All his actions were made from within a VNC session and it leaves no trace. He may have came from another proxy, but who knows… I still have a little hope that under legal request, the Internet provider of my relative will be able to provide some logs.
  • Nowadays, it is still difficult to report such a case to the police and to help the victim. The local police is at loss and does not really know what to do. The cyber section is slow to answer, probably crawling under requests (mostly spam stuff?).
  • Not every one has a computer specialist among friends or relatives. It must be a terrible experience to see the police coming to you for a fraud one hasn’t committed directly. Few people, even sometimes among IT professionals, understand that.
  • The criminal seemed low tech, but very organized at the same time.
    Here is my theory: he probably has a precise goal and is not loosing time.
    He follows a process: geo-localize the victim or target a country and choose accordingly financial data in his database.
    Then, he purchases stuff from a list of items he needs or he is requested.
    Finally, if he could not find a way to maintain access in seconds, he leaves. Mission done: this scammer is probably doing it full time, as a professional activity. Lame but efficient for the crime industry.
  • The credit card info was accompanied with private info: real name and address. We all know that but it is always shocking to think how it can easily obtained: compromised computer, hacked online shop or database, dishonest employee (e.g. at the hotel), etc.
  • The websites  will probably be used for more scamming and illegal activities. I am going to monitor the domain I got for a while.

Keep wired for updates.

Rootkit in my lab? (Part III)

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First, thanks for all the comments in the previous articles (Part I and Part II).

I decided to analyze one the crash I experienced during registry analysis.
I could reproduce all the time a BSOD with Regshot. I thought it would be nice to see what I could get with WinDBG.

I had my environment set up with the suspicious VM configured to debug activated on the serial port, which is a simple pipe on Mac OS X.
Another VM is configured with a serial port as the other end of this pipe, and WinDBG attached to it.
Another method would be to just configure Windows to create a crashdump file with kernel symbols, that you can later load into WinDBG. Of course, the first method offers more opportunities to check and play with the live system.

Then, I just boot the target and trigger the crash, simply by starting a scan with Regshot:

Windows then crashes, WinDBG catches the exception and stops.

So what do we have ?

First, the error type, PAGE_FAULT_IN_NONPAGED_AREA (50), means that an instruction pointed to an invalid memory address. Let’s check this.

With !analyse -v, you get the full error dump.

Crashing Instruction

It shows the function (nt!CmpGetValueKeyFromCache, offset 0×89) and the memory address where the crash was triggered.

The instruction at this address is:

80637807 f3a5 rep movs dword ptr es:[edi],dword ptr [esi]

This instruction is trying to copy 8 bytes at the address pointed by EDI.
EDI has the value of 0xe1285050 at execution time.

And what do we have at this memory location ?

EDI pointing to invalid memory section

Nothing indeed. Note that this corruption persists at every boot.

So what can we conclude?
We can certainly exclude hardware failure, because it is a virtual machine and because the corruption always occur at the same memory region, even after a reboot.
At least, I can now be sure that something in the kernel is definitely corrupted.

Could it be a rootkit trick? Still the question remains, but to me it now looks very, very suspicious. Some rootkit code, poorly written, could have sat in this non-paged memory area and been paged out, causing the BSOD. I have not much knowledge about it at this time but I am going to search on this. At least, I now have good starting point to look at.

That’s all for today, folks. I wrote it while I am still working on it, so sorry if it looks rough and incomplete. It is sort of live, thoughts are still in process.

Again, I am looking forward to reading your comments and suggestions. (Hopefully) there will be a part IV!

Rootkit in my lab? (part II)

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I finished checking the RAM with Volatility and… I found nothing. Nada.

It’s a lot of fustration. There must be something just there, but my findings are certainly limited by my skills.

I attach here some of the main outputs of Volatility. As far as I can tell:

  • no evidence of injection or kernel hooking
  • no suspicious process
  • no suspicious driver
  • no suspicious registry entry
  • etc.

Based on my observations, I first tried to narrow my investigations (drivers and hooks) but as I could not find anything, I ended dumping most of Volatility outputs in hope to see something unusual. I also compared them with a fresh Windows XP SP3 install. I extracted keyboard related drivers (keyboard.sys, kbdclass.sys, i8042prt.sys), hashed them, scanned them: there were native. I am less sure on how to deal with the software certificate system, but I did checked all Microsoft and root certificates in the bank along with their signature with a clean system: nothing wrong.

Dear reader, any help or tip is welcomed! Am I missing something obvious? Could it be possibly not a rootkit but some kind of corruption? If so, how to detect it?

Just drop me an e-mail if you want to have a look on the dump itself.

Volatility outputs:

Rootkit in my lab?

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Context

For now, I can’t tell much about the context, mainly because it may – or may not – involve other people. The only thing I am interested in is to spot the issue and understand precisely what is going on.

What makes the case really interesting though, is that it occurred on a fresh install of a Windows XP virtual machine. I aimed it to be a clean malware reversing snapshot. I noticed the weired behavior minutes after finishing the system install and setting up a bunch of reversing and live analysis tools.

So I bet that if I got some malware, it probably comes from one of those. At this time, unfortunately, there are too many and I could not spot the exact time, so I can not start the analysis from this angle.

This article is almost written in live, so pardon my mistakes. I will update it as soon as I find something new. Of course, I am really expecting your feedback, suggestions and corrections. I see it as a great opportunity to learn, even though this one may not be the easiest…

Symptoms

Two things alerted me quickly.

The first one was, at a point, the permanent failure of going through the full windows update process. Believe me, I have tried all ways.

The second one was the weird dialog when trying to access to the keyboard layout settings. It says “Incompatible driver detected“. To me, this looks like there is a keylogger somewhere…

Suspicious activities: the keyboard driver and windows update seem to be messed

Then, as I started to check around, more odd stuff came out.

I fired up Process Explorer, and soon realize that it was “unable to verify” the signatures of all the running Windows processes. I could not find anything else suspicious, though (no odd process, memory content looks normal, etc.).

On the left, Process Explorer fails to validate any Windows process.
On the right, expected behavior on a clean system.

Ok, while I am with the Sysinternal suite, why not scanning with Rootkit Revealer:

Rootkit Revealer cannot access to the SYSTEM hive of the registry

Interesting… and what about GMER:

GMER crashes when accessing the registry…

Oops! Now it crashes when it is accessing the registry…

For the fun, let’s see what happens if we try to set up an antivirus (Security Essentials):

Windows certificate warning when installing… Microsoft Security Essentials!!!

Nice one! Very suspicious! Note that after a full scan, Security Essentials reports me that the system is clean and everything is fine. I am so relieved. :)

Curious to see how my certificates are, I run certmgr.msc. I compared all Microsoft root certificates with a clean machine and could not see anything different. But again something happened:

certmgr.msc crashes

Oh, just one of my last attempts to do live analysis (this the WinPcap setup included with Wireshark):

WinPCAP installation also fails

Ok, so enough played. The thing seems to be nicely done, and live analysis is going to be way too hard and unreliable.

Memory Analysis

This is where I am now. I reverted to a snapshot prior to my live analysis attemps, confirmed the strange behaviors are still observable, and suspended the VM to get the vmem file.

So I have spent the last hours scanning the memory with, of course, Volatility.

So far, I have to confess that I found NOTHING. But analyzing the memory can be a harsh process when it comes to sophisticated threats, and I may have reached the limits of my skills.

But, anyway, I could not dream of a greater and more exciting opportunity to learn!

My discoveries, if there are, will be published in another article.

UPDATE: I forgot to tell that it is a Windows XP SP3 machine, but not fully updated due to the issues.

Soktspy

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Soktspy is a small script that may be helpful for some investigation.

Sometimes, you may detect that some suspicious network traffic coming out from a machine. In general, it is easy to spot the process from which the packets originate. You somehow connect to the PC and look for open sockets.

But sometimes, the behavior may be very sneaky, consisting of one or two packets, at rare and random intervals. Unless you spend all the day before the screen, it may be very difficult to trace.

Especially with stock tools or without installing any intrusive hardware, which is also the reason why I did this tool. On a production server, you want to install as little dependencies as possible, right?

So here is the Soktspy, a python script that easily build into a portable and standalone executable to deploy on the target machine.

Once launched, it just loops in the background and log sockets that are created for some given peers (the IP addresses you found involved in the suspicious network activity).

Maybe, some other tool exist, but I could not find anything similar. Let me know if you have any suggestion. Anyway, it was a nice exercise to do :)

Download

soktSpy v1.2

Pre-requisites

  • Install Visual C++ Runtime libraries with vcredist_x86.exe (not necessary if the target machine happens to have Python already installed)
So far, I tested it successfully on Windows XP, Windows 2003, Ubuntu 11.10 and Mac OS Lion. But as it is a simple Python script, it is supposed to work on all platform.

Compiling

You may recompile the program as a Windows binary executable by issuing this command:

> setup.py py2exe

How to use

  • Copy soktSpy.exe and its configuration file config.cfg.
  • Edit config.cfg with the IP you want to monitor
  • Start soktSpy.exe.

Then, as soon as the sneaky process will send out a packet toward the monitored IP, a log record will be triggered:

The log file contains the following info, in that order:

  • Detection time (based on the system local time)
  • Process creation time
  • PID
  • Process Name
  • Protocol Family (2 = IPv4, 23 = IPv6)
  • Process Owner
  • Source socket (IP, port)
  • Destination socket (IP, port)
  • Socket Status

Future Plans

Please tell me if you have any idea on how to improve it.

For now, I plan to add a feature that will dump the memory of the suspicious processes when it is executing.

Misc rants on Linux desktop, Mac OS and Antivirus

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Linux desktop is in bad shape…

The culprits? Unity and Gnome 3. I am not talking about KDE, as I never felt good with it. I had tried KDE 4 and it did not change my opinion, not to mention that I suffered from several bugs.

Unity? Like many people, I just don’t get it. It is pretty clumsy and feels unachieved. I also suffered from a lot of performance issues like this that are never fixed and make it a pain to use daily.
Gnome 3? Actually, I liked it. It looks nice, is pretty fast and smooth. What I like the most is the workflow. It really makes use of workspaces logical and optimum. But… it did not work for me! Instability, again and again.
You will tell me, that I should have stayed with Gnome 2 or go to XFCE / Openbox / etc. I have used all of them. They have qualities, sure, but we are in 2012 and I want something with more features.

Conclusion: it is sad that after so many years, Linux is not yet ready for the desktop, because some guys decided to break everything again instead of doing incremental enhancements. Why breaking so suddenly things that work? I don’t get it. I felt really fustrated with the feeling that I was at the same point as 5 years ago, dealing with the same kind of bugs. I have long been a Linux advocate and I believed I was right a few years back when I told people it was promising and superior to the competition (Windows XP at the time). Now years have passed, and I started to feel I was lying, or hiding the truth that is Linux Desktop failed and went nowhere.
Yes, I just got tired to fight with the computer to get basic things done. And considering the Linus post and several reactions into the comments, I am not alone in this case.

… so I gave a try to Apple…

I recently got a Mac Book Pro. The main reason is I wanted a very stable workstation to focus on my work. It was hard to admit after so many years using it, but I came to the conclusion that a Linux desktop could not meet this requirement anymore.

So I am going to be with Mac OS Lion for a while (though I am certainly not closing the door to the Linux desktop forever). I have to say that it is a nice OS and it is damned stable. It is good to have something that works out of the box, without any frustration or need to customize things to have something suitable.

And what about the stability of Mac OS? It is very eye candy, but is it stable?

At first, I actually had some serious troubles. It was freezing almost every day, forcing me to a cold reboot. I started to be seriously doubtful concerning the stability of Mac OS, when I found by chance that the freeze occured every time that Sophos Antivirus started an update…

Antivirus and Mac OS…

Wait, what? Antivirus? On Mac OS? I know it will be the reaction of many Mac users. I do also think that it is useless, but for a different reason than most of them.
Of course, I don’t get the “Mac OS is secure” marketing. Actually, it has the less secure kernel around, even though it benefits from a robust Unix architecture.
No, my point is that antivirus all fail anyway. In forensic analysis, we can even not trust an antivirus scan to decide if a machine is sane or not. Instead, we have to use specific tools and memory acquisition to make sure.
It is simply because signature-based detection can always be worked around by malwares. There are hundreds of ways to achieve it successfully: changing binary headers, code obfuscation, encryption, hooking (see rootkits and bootkits).
Ok, antivirus vendors claim that they also offer behavioral detection, sandboxes, etc. Yes, that’s a good move, but they can’t check all of the system activity and again there are many ways to bypass it. So why bother?

I mean, I still think it matters to have an antivirus on Windows. Especially for people who are not too techy. At least, it will detect the most basics threats and throw out alarms. There are thousands of such threats on Windows, and on this point antivirus offer a simple way to defeat them (though awareness and education are certainly more important).

But on Mac Os, and on Linux as well, there are very few threats. Once again, it is not that they are so much secure, but at the time I am writing, it is a fact.

So to summarize:

  • very few threats on Mac OS and Linux
  • antivirus still massively rely on signature-based detection

You see: if there is nothing much to detect, an antivirus is overhead. It will only eat some resources and fail anyway against coming threats.
Just keeping the system up-to-date is certainly the best thing to do so far.

Well, so why did I set an antivirus? I was actually using it for my forensic analysis on Windows machines. It was a convenient way for me to have a local scanner that I could started on dumped suspicious processes, without having to connect on Viruscan. It used to be convenient when I was traveling without connection, but I can live without it.

About Sophos for Mac OS

So moreover this piece of software was crashing my laptop. The update part seems to be executed with root privileges, and for some reason it locks the system (not only mine, look at the forums). Not to mention that having such a component may offer more room to malicious code to exploit the kernel…

A shame, a pure piece of crap. Now that I removed it, I am enjoying an uptime of about 30 days!

Conclusion

Sophos Antivirus for Mac OS is pure crap, run to remove it if it happens to be on your computer.

Anyway, you don’t need an antivirus on Mac OS. Moreover, it seems that several vendor offer solution that lack of maturity and testing on this platform. So you would actually degrade your system stability and security if you would installed on of these.

And Mac OS is a nice Unix-based desktop alternative to have the work done, even though sadly it is not open-source.