How can a program detect that it is running on Citrix? - virtualization

I am creating a program, which may or may not run inside a Citrix instance. The program needs to detect this, because it needs to behave in a different way on Citrix. How can it be detected in a reliable way? So far, my best guess was to check whether the computer has a C-drive.

I assume you want to know whether your application runs in a XenApp (aka Presentation Server / Metaframe) session?
Checking for the existence of drive C: is not the right way to do it. Historically, the drives letters on Citrix terminal servers were often remapped, e.g. from C: to M:. But this is not "en vogue" any more.
Please see my earlier answer for the correct way to determine the session type.
If instead you want to determine if XenApp/Presentation Server is installed, look up the corresponding registry values as described in Citrix Knowledgebase article CTX107570.

bool(os.environ.get('citrix_version'))
I think this is the best way to detect in python.

Related

Trigger reboot and script execution, securely

I am using PowerShell to manage Autodesk installs, many of which depend on .NET, and some of which install services, which they then try to start, and if the required .NET isn't available that install stalls with a dialog that requires user action, despite the fact that the install was run silently. Because Autodesk are morons.
That said, I CAN install .NET 4.8 with PowerShell, but because PowerShell is dependent on .NET, that will complete with exit code 3010, Reboot Required.
So that leaves me with the option of either managing .NET separately, or triggering that reboot and continuing the Autodesk installs in a state that will actually succeed.
The former has always been a viable option in office environments, where I can use Group Policy or SCCM or the like, then use my tool for the Autodesk stuff that is not well handled by other approaches. But that falls apart when you need to support the Work From Home scenario, which is becoming a major part of AEC practice. Not to mention the fact that many/most even large AEC firms don't have internal GP or SCCM expertise, and more and more firm management is choosing to outsource IT support, all to often to low cost glorified help desk outfits with even less GP/SCCM knowledge. So, I am looking for a solution that fits these criteria.
1: Needs to be secure.
2: Needs to support access to network resources where the install assets are located, which have limited permissions and thus require credentials to access.
3: Needs to support remote initiation of some sort, PowerShell remote jobs, PowerShell remoting to create a scheduled task, etc.
I know you can trigger a script to run at boot in System context, but my understanding is that because system context isn't an actual user you don't have access to network resources in that case. And that would only really be viable if I could easily change the logon screen to make VERY clear to users that installs are underway and to not logon until they are complete and the logon screen is back to normal. Which I think is really not easily doable because Microsoft makes it near impossible to make temporary changes/messaging on the logon screen.
I also know I can do a one time request for credentials on the machine, and save those credentials as a secure file. From then on I can access those credentials so long as I am logged in as the same user. But that then suggests rebooting with automatic logon as a specific user. And so far as I can tell, doing that requires a clear text password in the registry. Once I have credentials as a secure file, is there any way to trigger a reboot and one time automatic logon using those secure credentials? Or is any automatic reboot and logon always a less than secure option?
EDIT: I did just find this that seems to suggest a way to use HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon without using a plain text DefaultPassword. The challenge is figuring out how to do this in PowerShell when you don't know C#. Hopefully someone can verify this is a viable approach before I invest too much time in trying to implement it for testing. :)
And, on a related note, everything I have read about remote PowerShell jobs and the Second Hop Problem suggests the only "real" solution is to use CredSSP, which is itself innately insecure. But it is also a lot of old information, predating Windows 10 for the most part, and I wonder if that is STILL true? Or perhaps was never true, since none of the authors claiming CredSSP to be insecure explained in detail WHY it was insecure, which is to me a red flag that maybe someone is just complaining to get views.

Passing Parameters and Running Powershell Script

I'm unsure if what I'm trying to do is possible. I have a PowerShell script that takes three arguments. In a perfect world, I'd collect the necessary information in a web form and pass it to the script, which would then run.
I don't know if this is even possible, but I can't find anything that definitively tells me no. I'd need it to be cross-browser capable (we have some Macs) so I can't just do an IE-only fix.
This is also internal only, so I'm less concerned about some security risks. It will be behind our firewall.
Thanks.
Not sure to understand the question, but for collecting the necessary information in a web form and pass it to the script, which would then run I user PowerShell Web Server (tag : poshserver in stackoverflow). Sources are available, so I even implements Jobs for long scripts.

Which exploit and which payload use?

Hi everyone and sorry for my bad English.
I'm learning penetration testing.
After reconnaissance and scanning of my target, I have enough information to pass to next phase.
Some info I have is open ports with related running services, names of the services, service's versions, operative system of the device, firewalls used, etc.)
I launched the mfs console.
I should find the correct exploit and payload, based on the information collected to gain access. I've read the Metasploit Unleashed guide on offensive-security. I've learned the Metasploit Fundamentals and the use of mfs console.
But I don't understand the way to start all of this. Assuming that my target has 20 ports open, I want test the vulnerability using an exploit payload that do not require user interaction. The possibilities of which exploit and payloads to use are now reduced, but are always too. Searching and testing all exploit and payloads for each ports isn't good! So, if i don't know the vulnerability of the target, how do I proceed?
I would like to be aware of what I do. and do not try without understanding.
Couple of things:
We have a stack exchange for security! Check it out at https://security.stackexchange.com/
For an answer: you want to look for "remote exploits", as those do not require user interaction. you can find a curated list of exploits here: https://www.exploit-db.com/remote/
You can search the services on this page for something that matches the same service/version as your attack vector.

Determining a specific application's network transfer speed via command prompt?

My goal is to create a network activity light for a specific program. I'm a mechanical guy, so I can figure out the hardware and the logic, but I have no clue where to start with the coding. Ultimately this needs to run without user interaction, so I figured some sort of script would be a good place to start. I tried looking at netstat -e, but I didn't see any obvious way to determine the bandwidth a specific application was using. Thoughts? I'm using Windows 7.
I accomplished my goal using the "typeperf" command:
typeperf "\Process(FlashMediaLiveEncoder)\IO Data Bytes/sec"

What code to write for a dongle attached system to provide better security?

I have developed a software piece (with C and Python) which I want to protect with dongle so that copying and reverse engineering becomes hard enough. My dongle device comes with an api which provides these:
Check dongle existence
Check proper dongle
Write into a memory location in dongle
Read from a memory location in dongle etc. (I think the rests aren't that good..)
What I can do in the source code so that it becomes harder to crack. Dongle provider suggested that, I should check proper dongle existence in a loop or after an event, or I should use the dongle memory in an efficient way. But how? I have no idea how crackers crack. Please shed some light. Thanks in advance.
P.S: Please don't suggest obfuscating. I have already done that.
First of all, realize that the dongle will only provide a little bit of an obstacle. Someone who knows what they're doing will just remove the call to the dongle and put in a 'true' for whatever result that was called. Everyone will tell you this. But there are roadblocks you can add!
I would find a key portion of your code, something that's difficult or hard to know, something that requires domain knowledge. Then put that knowledge onto the key. One example of this would be shader routines. Shader routines are text files that are sent to a graphics card to achieve particular effects; a very simple brightness/contrast filter would take less than 500 characters to implement, and you can store that in the user space on most dongles. Then you put that information on the key, and only use information from the key in order to show images. That way, if someone tries to just simply remove your dongle, all the images in your program will be blacked out. It would take someone either having a copy of your program, grabbing the text file from the key, and then modifying your program to include that text file, and then knowing that that particular file will be the 'right' way to display images. Particulars of implementation depend on your deployment platform. If you're running a program in WPF, for instance, you might be able to store a directx routine onto your key, and then load that routine from the key and apply the effect to all the images in your app. The cracker then has to be able to intercept that directx routine and apply it properly.
Another possibility is to use the key's random number generation routines to develop UIDs. As soon as someone removes the dongle functionality, all generated UIDs will be zeroed.
The best thing to do, though, is to put a domain specific function onto the dongle (such as the entire UID generation routine). Different manufacturers will have different capabilities in this regard.
How much of a roadblock will these clevernesses get you? Realistically, it depends on the popularity of your program. The more popular your program, the more likely someone will want to crack it, and will devote their time to doing so. In that scenario, you might have a few days if you're particularly good at dongle coding. If your program is not that popular (only a few hundred customers, say), then just the presence of a dongle could be deterrent enough without having to do anything clever.
Crackers will crack by sniffing the traffic between your app and the dongle and either disabling any code that tests for dongle presence or writing code to emulate the dongle (e.g. by replaying recorded traffic), whichever looks easier.
Obfuscation of the testing code, and many scattered pieces of code that perform tests in different ways, as well as separating spatially and temporally the effect of the test (disabling/degrading functionality, displaying a warning etc.) from the test itself make the former method harder.
Mutating the content of the dongle with each test based on some random nonce created each run or possibly even preserved between runs, so that naively recording and replaying the traffic does not work, will make the latter method harder.
However, with the system as described, it is still straightforward to emulate the dongle, so sooner or later someone will do it.
If you have the ability to execute code inside the dongle, you could move code that performs functions critical to your application there, which would mean that the crackers must either rederive the code or break the dongle's physical security - a much more expensive proposal (though still feasible; realise that there is no such thing as perfect security).
How to maximize protection with a simple dongle?
Use API together with Enveloper if an enveloper exists for your resulting file format. This is a very basic rule. Because our enveloper is already equipped with some anti-debugging and obfuscating methods to prevent common newbie hackers to give up hacking the program. Only using enveloper is also not recommended, because once a hacker can break the enveloper protection in other program, they can also break yours.
Call dongle APIs in a LOT of places in your application. For example when first start up, when opening a file, when a dialog box opens, and before processing any information. Also maybe do some random checking even when there's nothing done at all.
Use more than one function to protect a program. Do not just only use find function to look for a plugged dongle.
Use multiple dlls/libraries (if applicable) to call dongle functions. In case one dll is hacked, then there are still other parts of the software that uses the functions from another dll. For example, copying sdx.dll to print.dll, open.dll, and other names, then define the function calls from each dll with different names.
If you use a dll file to call dongle functions, bind it together with the executable. There are quite some programs capable of doing this; for example PEBundle. 3
I have got this article on PRLOG and found it quite useful on maximizing protection with a simple dongle. Maybe this link may help you
Maximizing Protection with a Simple Dongle for your Software
You can implement many check points in your application.
I don't know if you use HASP, but unfortunatelly, dongles can be emulated.
You may want to look into using Dinkey Dongles for your copy protection.
It seems a very secure system and the documentation gives you tips for improving your overall security using the system.
http://www.microcosm.co.uk/dongles.php
Ironically, the thing you want to discourage is not piracy by users, but theft by vendors. The internet has become such a lawless place that vendors can steal and resell your software at will. You have legal recourse in some cases, and not in others.
Nothing is fool-proof, as previously stated. Also, the more complex your security is, the more likely it is to cause headaches or problems for legitimate users.
I'd say the most secure application is always the one tied closest to the server. Sadly, then users worry about it being spyware.
If you make a lot of different calls to your dongle, then maybe the cracker will just emulate your dongle -- or find a single point of failure (quite common to change one or two bytes and all your calls are useless). It is a no-win situation.
As the author of PECompact, I always tell customers that they can not rely on anything to protect their software -- as it can and will be cracked if a dedicated cracker goes after it. The harder you make it, the more of a challenge (fun) it is to them.
I personally use very minimal protection techniques on my software, knowing these facts.
Use smartcard + encrypt/decrypt working files through secret function stored in card. Then software can be pirated, but it will not able to open properly encrypted working files.
I would say that if someone wants to crack your software protection, they will do so. When you say 'hard enough' - how should 'enough' be interpreted?
A dongle will perhaps prevent your average user from copying your software - so in that sense it is already 'enough'. But anyone who feels the need and is able to circumvent the dongle will likely be able to get past any other scheme that you engineer.