Basically I need to download a .txt file to my teachers macbook saying something along the lines of "I was here" including my name & student ID.
If I can manage to do this I instantly pass the security class.
For those of you who want to hear (or read) the story, read the following paragraph, for the rest just skip it.
My teacher from my Computer Security class has given everyone a challenge, the one who leaves a txt file saying you were here on his macbook's desktop will instantly pass the class. He usually keeps an eye on his macbook and if you want access to it you'd have to steal it without him seeing you do it. His disk is encrypted and he has long passwords. I have thought about a few approaches and I want to get as much information on each approach as possible. First approach was simply hanging a recorder somewhere in the room to record him typing in his password then stealing his mac and creating the txt file. Second approach was somehow getting him to run a file that would create said txt file. And third approach is basically injecting javascript code into his sites which silently download the txt file to his desktop. Now I just need to know if it's even possible to silently download said file.
So here we finally come to the question, is there a way of silently downloading a txt file, and if so how would one do it?
And if it isn't possible, does anyone have any ideas for me to place the txt file on his pc?
EDIT: For those of you wondering, its uni/college not some kind of preschool.
Well, Have you performed any scans on this particular macbook? Do they host any services, like a web server or other service from this machine? That would be the traditional starting point.
Otherwise, Social Engineering, is probably the best way forward. You could pull off the student version of what happened to Ross Ulbricht. Wait for them to log into the machine. Then get some of your mates to create a significant distraction. Download and execute a quick executable that places your "proof" on the desktop (Or just be a quick typist) Profit.
Alternately:
Create a malicious executable.
Change the icon of executable to look like a word document.
Name Executable "Love Letter" or something juicy.
Place the executable on Flash Drive.
Place 5-10 "Boring" useless, normal files on there too. 2-3 pictures. (Just to get his guard down)
Leave this flash drive on or (Preferably near) his desk.
Wait.
This executable should create the text file on the desktop, pop up a smug message, Take a screenshot, and email both you and him the picture as proof.
The executable should also be designed to no longer work after a certain amount of time.
Related
On certain programs you can run them on a demo period for say 'ten tasks' or '5 hours' before you need to decide to purchase them to keep using them, but if you delete and uninstall the program then reinstall it, it knows that its been previously installed and wont let you run the demo again.
How does it do this ? When you download it does it send a identifiing number (ip ?) to the cdn to let it know youve downloaded it before, or when the program itself installed does it check to see traces of previous installation ?
Most "demo" software does this by a feature borrowed from malware: Incomplete deinstallation. A file or registry key belonging to the software is not removed on deinstallation. On reinstallation the software sees the remainder and can act on it.
Often-used hiding places for such a remainder were the system directory (before UAC arrived), but many register some class GUID - nobody I know of has a real overview of which classes in the registry are or are not genuine.
There are many ways this can be implemented.
The easiest way to implement (and also the easiest way to bypass)
On first run, create a registry (or text file) entry somewhere
Add 1 to the counter every time the task (or the app) is run
Do not include this file/registry in the installer app (so it will persist after uninstallation)
If at any time the count is too high, notify the user that the trial has expired.
Using image diff tools this method is pretty easy to identify and overcome.
The hardest method to overcome or bypass is to use a server. On the first run, generate a hash code based on the users computer name, drive serial number, etc, and post this to your server. The server then tracks this as a unique installation, and allows the app to run. Each time you run the app, you update the server. This way, the user cannot find the breadcrumbs and delete them, since they are on your server. The down side, is that this method will require an Internet connection.
There are probably much more sophisticated methods to achieve this result, but the above are both implementations I've run across.
My software drops breadcrumbs within the users system which is used to check for previous installations. This is a little harder to get around (assuming you don't know what you are looking for, or where) than an internet check against your IP. As you can always spoof your connection information, or just disconnect from the internet while installing.
I am trying to figure out when and how does Windows update File Access Times on files.
First of all, most Windows installs come with File Access Times disabled for performance reasons, so before wrapping your head around it here is what you need to do in order to activate last access times on NTFS file systems: modify the key [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem] value name NtfsDisableLastAccessUpdate to DWORD 0 value data(if it is set to 1 of course). If it doesn't exist just create it.
Upon reading File Times article on MSDN i am still in doubt as to how Windows updates access times.
My questions are as follow:
Do access times update upon issuing a WinApi CreateFile() with FILE_READ_ATTRIBUTES ? In my case, while doing it programmatically, it doesn't. Opening up the File Properties dialog of that file through the Explorer Shell does update the access time.
Do access times update upon issuing a WinApi ExtractIconEx() to read an icon from a file?
In my case doing so programatically, it doesn't. Opening up the File Properties dialog of that file through the Explorer Shell does update the access time.
If you ask me, both of those cases should update the file access times, but it seems to me that direct WinApi calls don't update them or Window/NTFS driver really lags behind, while operating on files from Windows Explorer do update pretty well. What do you think is or could be the issue here?
As a side note, i did do CloseHandle() as per:
The only guarantee about a file
timestamp is that the file time is
correctly reflected when the handle
that makes the change is closed.
My end conclusion is that, indeed the opinions lying around the web are true and Windows does update File Access Times in a random fashion and thus one really shouldn't in no way depend on Windows File Access Times.
Off-topic rant: Sorry forensics guys, you'll have to prove access times using another method or you can have your case invalided in seconds. :P
No, accessing the metadata of the file isn't going to change the last access time (name, attributes, timestamps). Wouldn't work well in practice, just looking at the directory with Explorer would change it. You have to actually open the file. ExtractIconEx() would normally be an excellent candidate, except that Windows can play tricks with it. A hidden desktop.ini file can redirect the icon to another file.
Using the last access time is pretty worthless for forensics. You'd need a file system filter driver. Similar to the one embedded in SysInternals' ProcMon utility. It might be using ETW btw, that got pretty powerful at Vista time. Nevertheless, your project just got 10 times more complicated.
I am in the middle of writing a tool that finds lost files of an iTunes library, for both Mac and Windows. On the Mac, I can quickly find files by naming using the wonderful "CatalogSearch" function.
On Windows, however, there seems to be no OS API for searching by file name (or is there?).
After some googling, I learned that there are tools (like TFind, Everything) that read the NTFS directory directly and scan it to find files by name.
I would like to do the same, but without having to start from scratch (although I've written quite a few disk tools in the past, I've never had the energy to dig into NTFS).
I wonder if there are ready-made libs around, possibly as a .dll, that would give me this search feature: Pass in a file name, get back its path.
Alternatively, what about the Windows indexing service? At least when I tried this on a recently installed XP Home system, the Search operation under the Start menu would actually scan all directories, which suggests that it has no complete database. As I'm not a Windows user at all, I wonder why this isn't working.
In the end, the complete solution I need is: I have a list of file names to find, and I need code that searches the entire disk (or uses a DB for it) to get me all results in one go. E.g, the search should not start a new full scan for every file I'm looking up. That's why I think the MFT way would be optimal, as it could quickly iterate over all names, comparing each to my list.
The best way to solve your problem seems to be by using the Windows Change Journal.
Problem: If it is not enabled for a volume or the volume is a non-NTFS you need a fallback (or enable the Change Journal if it is NTFS). You need administrator rights as well to access the Change Journal.
You get the files by using the FSCTL_ENUM_USN_DATA and DeviceIOControll with LowUsn=0. This directly accesses the MFT and writes all filenames into the supplied buffer. Because it sequentially acesses the MFT it is faster than the FindFirstFile API.
I am in the middle of writing a tool that finds lost files of an iTunes library, for both Mac and Windows. On the Mac, I can quickly find files by naming using the wonderful "CatalogSearch" function.
On Windows, however, there seems to be no OS API for searching by file name (or is there?).
After some googling, I learned that there are tools (like TFind, Everything) that read the NTFS directory directly and scan it to find files by name.
I would like to do the same, but without having to start from scratch (although I've written quite a few disk tools in the past, I've never had the energy to dig into NTFS).
I wonder if there are ready-made libs around, possibly as a .dll, that would give me this search feature: Pass in a file name, get back its path.
Alternatively, what about the Windows indexing service? At least when I tried this on a recently installed XP Home system, the Search operation under the Start menu would actually scan all directories, which suggests that it has no complete database. As I'm not a Windows user at all, I wonder why this isn't working.
In the end, the complete solution I need is: I have a list of file names to find, and I need code that searches the entire disk (or uses a DB for it) to get me all results in one go. E.g, the search should not start a new full scan for every file I'm looking up. That's why I think the MFT way would be optimal, as it could quickly iterate over all names, comparing each to my list.
The best way to solve your problem seems to be by using the Windows Change Journal.
Problem: If it is not enabled for a volume or the volume is a non-NTFS you need a fallback (or enable the Change Journal if it is NTFS). You need administrator rights as well to access the Change Journal.
You get the files by using the FSCTL_ENUM_USN_DATA and DeviceIOControll with LowUsn=0. This directly accesses the MFT and writes all filenames into the supplied buffer. Because it sequentially acesses the MFT it is faster than the FindFirstFile API.
UNIX file-locking is dead-easy: The operating system assumes that you know what you are doing and lets you do what you want:
For example, if you try to delete a file which another process has opened the operating system will usually let you do it. The original process still keeps it's file-handles until it terminates - at which point the the file-system will quietly re-cycle the disk-resources. No fuss, that's the way I like it.
How different things are on Windows: If I try to delete a file which another process is using I get an Operating-System error. The file is untouchable until the original process releases it's lock on the file. That was great back in the single-user days of MS-DOS when any locking process was likely to be on the same computer that contained the files, however on a network it's a nightmare:
Consider what happens when a process hangs while writing to a shared file on a Windows file-server. Before the file can be deleted we have to locate the computer and ID the process on that computer which originally opened the file. Only then can we kill the process and delete our unwanted file.
What a nuisance!
Is there a way to make this better? What I want is for file-locking on Windows to behave a like file-locking in UNIX. I want the operating system to just let me do what I want because I'm in charge and I know what I'm doing...
...so can it be done?
No. Windows is designed for the "average user", that is people who don't understand anything about a computer. Therefore, the OS tries to be smart to avoid PEBKACs. To quote Bill Gates: "There are no issues with Windows that any number of people want to be fixed." Of course, he knows that 99.9999% of all Windows users can't tell whether the program just did something odd because of them or the guy who wrote it.
Unix was designed when the world was more simple and anyone close enough to a computer to touch it, probably knew how to assemble it from dirty sand. Therefore, the OS usually lets you do what you want because it assumes that you know better (and if you didn't, you will next time).
Technical answer: Unix allocates an "i-nodes" if you create a file. I-nodes can be shared between processes. If two processes create the same file (that is, two processes call create() with the same path), then you end up with two i-nodes. This is by design. It allows for a fancy security feature: You can create files which no one can open but yourself:
Open a file
Delete it (but keep the file handle)
Use the file any way you like
Close the file
After step #2, the only process in the universe who can access the file is the one who created it (unless you want to read the hard disk block by block). The OS will keep the data alive until you either close the file or your process dies (at which time Unix will clean up after you).
This design is the foundation of all Unix filesystems. The Windows file system NTFS works much the same way but the high level API is different. Many applications open files in exclusive mode (which prevents anyone, even backup programs) to read the file. This is even true for applications which just display information like PDF viewers.
That means you'll have to fix all the Windows applications to achieve the desired effect. If you have access to the source, you can create a file in a shared mode. That would allow other processes to access it at the same time but then, you will have to check before every read/write if the file still exists, whether someone has made changes, etc.
According to MSDN you can specify to CreateFile() 3rd parameter (dwSharedMode) shared mode flag FILE_SHARE_DELETE which:
Enables subsequent open operations on a file or device to request delete access.
Otherwise, other processes cannot open the file or device if they request delete access.
If this flag is not specified, but the file or device has been opened for delete access, the function fails.
Note Delete access allows both delete and rename operations.
http://msdn.microsoft.com/en-us/library/aa363858(VS.85).aspx
So if you're can control your applications you can use this flag.
Note that Process Explorer allow for force closing of file handles (for processes local to the box on which you are running it) via Handle -> Close Handle.
Unlocker purports to do a lot more, and provides a helpful list of other tools.
Also deleting on reboot is an option (though this sounds like not what you want)
That doesn't really help if the hung process still has the handle open. It won't release the resources until that hung process releases the handle. But anyway, in Windows it is possible to force close a file out from under a process that's using it. Process Explorer from sysinternals.com will let you look at and close handles that a process has open.