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Let’s Unpack: Dridex Loader

A few people have been having problems with unpacking the initial loader for Dridex (the one dropped by the macro), so I’m going to show you an easy way to do it. One of the other problems people have, which i can’t fix, is the fact the Dridex infection chains have …

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Necurs.P2P – A New Hybrid Peer-to-Peer Botnet

Last week I received a tip about a sample displaying some indication that it could be peer-to-peer (a large amount of UDP traffic being sent to residential IPs), after a couple days of analysis I was able to confirm that not only was it peer-to-peer but also currently active. The person …

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Kelihos Analysis – Part 1

In the recent years I’ve noticed a shift in the malware economy from botnets to ransomware, which is likely due to the AV industry employing more aggressive tactics against botnets resulting in a drop in profitability. As I’ve said before: ransomware is about as interesting to me is watching oil …

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Windows 10 System Call Stub Changes

Recently I installed Windows 10 RTM and while I was digging around I happened to notice some changes to the user mode portion of the system call stub: these changes appear to break the current methods of user mode system call hooking on x86 and WOW64 (Recap: here). Windows 10 x86 …

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Hard Disk Firmware Hacking (Final)

Core 2, I choose you. Less than 5 minutes after posting the last article, i discovered the final piece of my puzzle: a second CPU core. I was looking through my OpenOCD configuration when I realized it had a single tap definition hardcoded, so i decided to comment it out …

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Hard Disk Firmware Hacking (Part 5)

“Discovery requires experimentation” This weekend I made a pretty big breakthrough which lead to me making a few smaller breakthroughs and ultimately negating most of my previous research. I’ve also learned that “not reinventing the wheel” isn’t always the best option, especially when it comes to trusting other people’s research. …

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Hard Disk Firmware Hacking (Part 4)

It seems that the bootstrap code is just scattered around various memory addresses and there’s no simple way to dump all of it, so i decided to just dump a chunk of memory from 0x00000000 and look for any reference to addresses outside of that chunk (allowing me to build …

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Hard Disk Firmware Hacking (Part 3)

Before we get started with part 3, I have a few updates regarding part 1 & 2. I’ve found that the reset pad on the JTAG header is not actually a system reset (SRST) but a TAP reset (TRST), which isn’t very useful for debugging. Here is the updated layout …

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Hard Disk Firmware Hacking (Part 2)

Now that everything is ready to be connected, power up the hard drive an run openocd with the following command: openocd -f interface/<your interface here>.cfg -f target/test.cfg test.cfg should be the configuration for the CPU used by your hard disk controller, for most marvell CPUs this config should work. I’m …

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Hard Disk Firmware Hacking (Part 1)

I’ve not been doing much in the windows malware world for a while now, because quite frankly I’ve run out of ideas and I’m totally bored. Recently I decided to take the jump into electronics / hardware hacking and people have suggested I post some of that here. A couple …