Windows 7 Loader 2.2.2 Download
Sandra Dunemn
Your DllMain function runs inside the loader lock, one of the few times the OS lets you run code while one of its internal locks is held. This means that you must be extra careful not to violate a lock hierarchy in your DllMain; otherwise, you are asking for a deadlock.
The loader lock is taken by any function that needs to access the list of DLLs loaded into the process. This includes functions like GetModuleHandle and GetModuleFileName. If your DllMain enters a critical section or waits on a synchronization object, and that critical section or synchronization object is owned by some code that is in turn waiting for the loader lock, you just created a deadlock:
Loader refers to the OS (module) loader.Loader Lock is a system lock used by the loader to synchronize calls to DllMain.This way, the loader ensures that initialization / cleanup tasks required by DLLs are performed in a thread-safe manner.
(...) the operating system has its own internal process-specific lock that sometimes is held while your code executes. This lock is acquired when DLLs are loaded into the process, and is therefore called the 'loader lock.' The DllMain function always executes under the loader lock; (...)
I clean installed windows 7 in legacy BIOS mode on a primary partition. I created two logical partitions for file storage. Ubuntu 16.10 was installed later using bootable USB by selecting the option 'Install alongside windows'. I think the setup created an ext4 partition to install Ubuntu.
Now when I switch on, Grub2 offers options to boot 'Ubuntu' and 'Windows 7 loader'. When I select 'Windows 7 loader' sometimes the black loader appears properly with options to boot Windows 7 or Ubuntu. But sometimes the screen just displays slanting dashed lines through.Slanted dashed lines.However instead of pressing 'Enter' on 'Windows 7 loader' option if I press 'E' I am presented with a code that can be modified.
Created a entry for Ubuntu in the loader and selected Syslinux as the type. Works. But it takes some additional time while booting to get into Ubuntu. (My diskmanagement tool shows that windows doesn't recognize the partitions Ubuntu was installed in. Probably because it recognizes only four partitions)
I hav a Dell inspiron 3000 working on windows 10. I recently installed ubuntu 16.04. The problem is that now when I boot Grub boot loader gives the options and I'm not very fond of it. I would like the windows boot loader (the GUI). Pls help me with the steps to do so
If you are not fond of grub than you can try BURG. It has better GUI than the windows boot loader (Trust me on this one). You can select different themes for that as well. Also if you have dual booted your system then you can remove other options from the options screen and set just two options i.e WINDOWS and LINUX. To know how to install BURG here is the link :How to install BURG on Ubuntu 16.04
What's the best way to remove windows loader 2.2.1 by daz? I recently bootcamped my MacBook and bought a legit copy of windows, I just hadn't activated it yet and one day being bored at work (and mostly out of curiosity) activated my windows using the daz loader.
Plus im worried i could get in trouble through my company... how easy would it be for the computer department to see I am using a non payed for copy of windows considering I downloaded and installed the loader on my windows username that is on the company domain
However, in windows I can go to System recovery -> advanced startup -> troubleshoot -> advanced options -> UEFI firmware settings -> F9 Boot Menu and at this point it shows me 2 boot loaders: one for windows (at top) and one for ubuntu (2nd). I can select one or the other, but cannot change the order. If I select the ubuntu loader, it starts grub, shows me an option for windows as well as ubuntu, and will boot ubuntu if selected.
I have read that the PE loader is responsible for loading executable images from disk. When and where is the control flow exactly transferred to the loader? The PE format is well documented but there seems to be a little info regarding the functioning of the loader itself.
The PE loader is exposed by a set of user APIs in kernel32.dll, under the CreateProcess family. There are different APIs for doing different things, e.g. running a process under an alternative security context.
The tricky part with your question is that the "loader" isn't really something that gets control flow. The instant you call CreateProcess, you're technically running the loader. However, the kernel part of the loader begins when ntdll!NtCreateUserProcess transitions into kernel-mode. If we're really strict about it, we might say that the first part of the loader is PspAllocateProcess, since that's what allocates the initial structures.
In the book Mastering Malware Analysis: The complete malware analyst's guide to combating malicious software, APT, cybercrime, and IoT attacks [Alexey Kleymenov, Amr Thabet], there're 2 sections in chapter 2 called "Process loading step by step" and "PE file loading step by step" which document how the Windows PE loader is loaded and how it works.
A loader is code that prepares other code for execution. Loaders take data
corresponding to a program or library and prepare it to be read, modified, and/or executed. This preparation process typically involves steps such as parsing a file containing the code to be run, metadata about that code, and other relevant bits of information such as the external services it might need from other parts of the operating system. Additionally, things like resolving external dependencies - or other, external bits of code the bit being prepared will rely upon, setting memory protections appropriately, and perhaps updating references (if the code is not position independent) will happen here.
Nearly all modern consumer-facing operating systems contain loaders. Loading occurs during the initialization of a process (when the primary application image is loaded), and also may occur in an ad-hoc fashion throughout program execution, as dynamic libraries (to include .dlls, .dylibs, and .sos, for example) are loaded and unloaded.
In the context of things like threat emulation, there is a strong desire to model trends present within the modern malware ecosystem - including the ability to operate in memory only. This presents a bit of a challenge: in Windows, for example, the operating system's built-in loader
only accepts binary files on disk. What we desire is a reflective loader
that will perform some of the same kinds of preparations that the native operating system's loader would handle, but without the requirement that the loaded binary reside on disk (note that some operating systems, such as MacOS, have facilities for executing directly in-memory natively).
The reflective_loadlibrary function accepts three arguments. First, it accepts
a loader_ctx, which contains a pointer to a structure we will use to manage contextual information that the loader will need as we implement it. Next, it accepts a buffer and its corresponding size, which represent the module that we wish to load. The function returns a LoaderStatus, which is a type we've created to help provide status results around success or failure as loader development progresses.
The Portable Executable (PE) format is a file format for executables, DLLs, Drivers, and some more exotic kinds of files on 32- and 64-bit versions of Windows. It contains all the information Windows needs to load and execute the specified module. Since we're re-implementing some of the Windows loader's functionality, we'll also need to parse PE files during the course of loading and executing.
For robustness, we'll want to verify that the buffer that our reflective loader receives is actually a PE file. A simple validation technique is to check that (a) the e_magic value is correct, and (b) that the RVA of the NT headers resides within the bounds of our buffer. The code snippet below illustrates how we might perform these checks.
The first field is a bit poorly named, as it is actually an RVA, coupled with a size. We will visit quite a few of these table entries as we progress through the loader development sections that follow.
While many allocator APIs exist in Windows, some special considerations must be applied to requesting memory for our loader. In particular, we have some special alignment and protection requirements (in general) that we will need to adhere to in order to ensure that our program will perform properly once loaded.
To keep things simple, we will start with VirtualAlloc, but keep in mind that other options exist, and may have different implications in terms of how our memory footprint looks forensically. So how much space should we get? In order to obtain that information, we should refer back to the IMAGE_OPTIONAL_HEADER structure from the last section, in particular, the SizeOfImage field. Thus, we can update our loader method as follows:
Here I am interested in restoring access from Fedora boot loader to my Windows 10 installation. (I had a Linux Mint in place of Fedora, and Mint had access to Windows but not to Solus. I have thought that replacing Mint with Fedora would fix the problem: it did not, it added a new one.)
thanks a lot! getting closer and closer The Grub menu appears when I boot Fedora in Bios but if I turn on the laptop it will start windows directly. Is it something I need to configure in Windows so it recognizes a dual boot?
so this takes me back to the question, will the loader fill our IAT when its loading the PE into memory by checking the export tables, or when our program uses it? because if its the first case then I assume there is no way to hook the export table right?
hey, I have windows xp and suse dual booted
or at least I did, the file system of suse developed a fault, and I had to run the repair scanner on the suse dvd.
out of many things it found wrong it claimed something was wrong with my boot loader, so when I let it get on with it, suddenly suse and failsafe suse was the only 2 listed, windows was gone, so I tried to manually add windows back.
I went to /mnt/windows/C/boot.ini