is Account Unknown(S-1-5-21-235848236-322578882-4173758772-1003) Trace of Hack or Malware or part of Windows?

Question

i went in to C:\Users & i left clicked on my user folder & then properties & Security & what i see is Account Unknown(S-1-5-21-235848236-322578882-4173758772-1003)

is it cause this folder is shared? or is it Hack? or is it malware/VIrus? or Part of Windows?

When i Google Account Unknown(S-1-5-21-235848236-322578882-4173758772-1003) i find nothing & when i Google Account Unknown(S-1-5-32-547) i find a lot, & i heard that Account Unknown(S-1-5-32-547) is part ow some win operation, but Account Unknown(S-1-5-32-547) & Account Unknown(S-1-5-21-235848236-322578882-4173758772-1003) are not same, well they don't seem same cause mine has longer number, or is it Microsoft acc, well when i got the PC i mixed things up & i made Microsoft acc & loged in PC with Microsoft acc & later made local acc, so is it the sing of my Microsoft acc with what i logged in to PC when i turned PC on first time?

Answer 1

Hi Sugram,

Thank you for replying with the status of the issue, I am sorry for delay in response.

There is no harm for your computer if the Account unknown is showing or removed from the accounts properties list as it is just a replica of the Microsoft account that you initially created to login to the computer, which is no longer in use.

I suggest you to leave the Account Unknown(S-1-5-21-235848236-322578882-4173758772-1003 in the Accounts properties > Security Tab list as it will not effect your computer or its performance. 

If you still concerned about the Account Unknown, take a backup of that account unknown and remove it from the computer please refer to my previous suggestion.

Hope this information helps, please reply if you need further assistance.

Answer 2

It's reassuring to know that "Accounts Unknown" are phantoms — perhaps a Windows installer's lost soul, haunting a Registry from the past. And it's certainly wise to ignore them, since apparitions mess only with true believers. Windows 10, however, is the wildly superstitious type — screaming Event Viewer warnings whenever Edge fails to make contact with one of these pesky poltergeists during a boot-up seance. 

Exorcism seems the only solution.

Answer 3

Hi. I just found this thread and I am having the same issue along with some other issues that all started Thursday Sept 8. I have two of them: Account Unknown(S-1-5-21-1815995351-3488429410-2291634709-1005) and Account Unknown(S-1-5-21-1815995351-3488429410-2291634709-1007)

I just tried your suggestion:

1. Go to Control Panel.
2. Search for User Accounts.
3. Click on Manage another account.

Neither of the Account Unknown,,, is listed there, they are only listed in security tab of any object or document I have. I have only ever installed myself (as administrator) and guest account has never been, and is not now enabled. Other problems that started Thursday: I opened Chrome and typed quizlet.com?login (teaching resource) in the address bar. During the typing, before I hit enter, Chrome was hi-jacked. I am still trying to find malware that may have been installed. I was running McAfee LiveSafe which came on the HP laptop I have. McAfee has proven to be worthless with this. It was somehow corrupted in this trainwreck and could not be repaired either manually or automatically by MVT.exe. I uninstalled McAfee. Windows Defender and Firewall is updated and now protecting my system. I have tried AMWB, Adwcleaner, MBAM. None of them fing a problem, but something is not right. 

My question is, Is the Unknown Account related to this? I have googled extensively these problems and found several answers. None of them have worked. I need help. 

Just a side note. The only thing that changed in the last month on my PC:

1.)  I let windows update install new driver Realtek Semiconductor Corp. WLAN software update released in August, 2016

2.) I installed Samsung USB driver for mobile phone and **KIES,**both from samsung.com (signed by samsung)

Any suggestion, any tools that I haven't already ran, any other thread or forum to read, anything at all would be extremely helpful. I am almost out of hair to pull out of my head.

Answer 4

This account unknow is set by Malware, it authomated default migration setting, if you had been previousely infected in one pc and buy a new one, there is no escape , it will bring every thing from infected pc to the new on, but it pretty very easy to remove. 

what it does it will clone you, it will then crate another controll real microsoft window, every thing is the same, but some time the update is not there but you where sure you install update, You see, this computer never had update, this is the time you know the window was swap, this is where you will have no permission in your own pc, you where there in the real microsoft window, but most people will not realised that is another window , and no update in that window, if you do not disturb it, everything work normall. 

This is how to remove these uknown administrator, swich off internet connection, go to window firewall, look for what is "YOUR ACCOUNT", follow the same line  orizontally to right at that end  you will either see those numbers S-!-5-- or NT AUTHORITY\ or just any name, delete it in both in and out. You will see a lof of  repeated file and printer shearing  and a lot of remote port, just block it all. now you are aware that you have deleted , go back again and check, you will find that it is infact reinserted it back, delete it again and that is the end , it will not comeback.

Now Press Flag + R

Type " Control userpasswords2" You can now see those unknown account in the open, you can revove it, yo can see some other users there too, the best things, double click everthing you see one by one, go to property, change them with yoursel as administrator and that is the the end. but now, your window will want to start rebooting and it will hung out,  it is because you have remove the root environment which was set by that unknown administrators. just use the phisical switch to turn your pc off, if it does not open do it again, then the window will choose your enviroment authomatically and reboot corectly, you will not see those imposter any more.

Answer 5

I stumbled into this thread late tonight when I realized I had MANY unknown accounts being added to permissions on many files, or all my files for that matter. I found this to be caused by changing from local account to Microsoft accounts AND in my case, reactivation after major hardware changes.

Background: My mainboard died taking with it the CPU and memory. During the repair the first motherboard died in 48 hours. So I had to again activate windows with my MS ID, as it is digitally linked and made the activation process easier. Each time I a got windows activated, I reverted back to local account, and it added yet another unknown account to the list.

Although everything is working properly the OCD in me does not like all these permissions added that are 'unknown' in name. With all the event viewer weirdness in Windows 10, DCOM errors for instance, it frustrates me that I cannot accomplish a (critical) error free OS. My system runs well, don't get me wrong, but I would like a clean'ER event log, and it seems to me when permissions start to have numerous erroneous accounts, this will lead to problems down the road. Maybe not, but with the complicated routine to deal with these accounts and the potential for catastrophic outcomes, I would feel better if the OS would deal with this more efficiently or at least identify these account with more detail. Keeping people from knee jerk reactions (virus, hacking etc) and start doing things in a dangerous playground, and deleting and changing settings out of panic.