Cygwin can't ssh (hangs, segmentation fault)?

I have cygwin installed on Windows 10 and am seeing that I cannot SSH to any of my servers. When trying to ssh, I just see

➜  ~ ssh -vv me@myserver
OpenSSH_8.4p1, OpenSSL 1.1.1f  31 Mar 2020

and it just hangs from there. Running the command with strace shows...

➜  ~ strace ssh -vv me@myserver
--- Process 29820 created
--- Process 29820 loaded C:\Windows\System32\ntdll.dll at 00007fff58a80000
--- Process 29820 loaded C:\Windows\System32\kernel32.dll at 00007fff58060000
--- Process 29820 loaded C:\Windows\System32\KernelBase.dll at 00007fff55cf0000
--- Process 29820 loaded C:\Windows\System32\sysfer.dll at 0000000075450000
--- Process 29820 loaded C:\cygwin64\bin\cygcrypto-1.1.dll at 00000003ff980000
--- Process 29820 loaded C:\cygwin64\bin\cygwin1.dll at 0000000180040000
--- Process 29820 loaded C:\cygwin64\bin\cyggssapi_krb5-2.dll at 00000003ff1f0000
--- Process 29820 loaded C:\cygwin64\bin\cygz.dll at 00000003fdc80000
--- Process 29820 loaded C:\cygwin64\bin\cygk5crypto-3.dll at 00000003feff0000
--- Process 29820 loaded C:\cygwin64\bin\cygkrb5-3.dll at 00000003fef20000
--- Process 29820 loaded C:\cygwin64\bin\cygkrb5support-0.dll at 00000003fef00000
--- Process 29820 loaded C:\cygwin64\bin\cygcom_err-2.dll at 00000003ffea0000
--- Process 29820 loaded C:\cygwin64\bin\cygintl-8.dll at 00000003ff030000
--- Process 29820 loaded C:\cygwin64\bin\cyggcc_s-seh-1.dll at 00000003ff530000
--- Process 29820 loaded C:\cygwin64\bin\cygiconv-2.dll at 00000003ff080000
    0       0 [main] ssh (29820) **********************************************
  175     175 [main] ssh (29820) Program name: C:\cygwin64\bin\ssh.exe (windows pid 29820)
  186     361 [main] ssh (29820) OS version:   Windows NT-10.0
  228     589 [main] ssh (29820) **********************************************
--- Process 29820 loaded C:\Windows\System32\advapi32.dll at 00007fff58830000
--- Process 29820 loaded C:\Windows\System32\msvcrt.dll at 00007fff56b30000
--- Process 29820 loaded C:\Windows\System32\sechost.dll at 00007fff57ec0000
--- Process 29820 loaded C:\Windows\System32\rpcrt4.dll at 00007fff57a80000
--- Process 29820 loaded C:\Windows\System32\cryptbase.dll at 00007fff55360000
--- Process 29820 loaded C:\Windows\System32\bcryptprimitives.dll at 00007fff55ac0000
18353   18942 [main] ssh (29820) sigprocmask: 0 = sigprocmask (0, 0x0, 0x180324D70)
  600   19542 [main] ssh (29820) open_shared: name shared.5, n 5, shared 0x180030000 (wanted 0x180030000), h 0xF8, *m 6
   74   19616 [main] ssh (29820) user_heap_info::init: heap base 0x800000000, heap top 0x800000000, heap size 0x20000000 (536870912)
   81   19697 [main] ssh (29820) open_shared: name S-1-5-21-749102807-3637569557-2173886209-22663.1, n 1, shared 0x180020000 (wanted 0x180020000), h 0xF4,
*m 6
   68   19765 [main] ssh (29820) user_info::create: opening user shared for 'S-1-5-21-749102807-3637569557-2173886209-22663' at 0x180020000
   64   19829 [main] ssh (29820) user_info::create: user shared version AB1FCCE8
   75   19904 [main] ssh (29820) fhandler_pipe::create: name \\.\pipe\cygwin-e022582115c10879-29820-sigwait, size 11440, mode PIPE_TYPE_MESSAGE
  130   20034 [main] ssh (29820) fhandler_pipe::create: pipe read handle 0x10C
  150   20184 [main] ssh (29820) fhandler_pipe::create: CreateFile: name \\.\pipe\cygwin-e022582115c10879-29820-sigwait
  163   20347 [main] ssh (29820) fhandler_pipe::create: pipe write handle 0x110
  190   20537 [main] ssh (29820) dll_crt0_0: finished dll_crt0_0 initialization
--- Process 29820 loaded C:\Program Files (x86)\Citrix\ICA Client\epclient64.dll at 00007fff31030000
--- Process 29820 loaded C:\Windows\System32\user32.dll at 00007fff57d20000
--- Process 29820 loaded C:\Windows\System32\win32u.dll at 00007fff55a10000
--- Process 29820 loaded C:\Windows\System32\gdi32.dll at 00007fff57060000
--- Process 29820 loaded C:\Windows\System32\gdi32full.dll at 00007fff56990000
--- Process 29820 loaded C:\Windows\System32\msvcp_win.dll at 00007fff568d0000
--- Process 29820 loaded C:\Windows\System32\ucrtbase.dll at 00007fff55bf0000
--- Process 29820 loaded C:\Windows\System32\version.dll at 00007fff507c0000
--- Process 29820 loaded C:\Windows\System32\imm32.dll at 00007fff58800000
--- Process 29820 loaded C:\Windows\System32\ntmarta.dll at 00007fff54910000
--- Process 29820, exception c0000005 at 00000001801505d4
--- Process 29820 thread 27924 created
--- Process 29820, exception c0000005 at 0000000180062287
--- Process 29820 thread 27924 exited with status 0x0
--- Process 29820, exception c0000005 at 0000000180062287
--- Process 29820, exception c0000005 at 0000000180062287
--- Process 29820, exception c0000005 at 0000000180062287
.
.
.
--- Process 29820, exception c0000005 at 0000000180062287
--- Process 29820, exception c0000005 at 00007fff58a9e626
--- Process 29820 exited with status 0xc0000005
[1]    451 segmentation fault  strace ssh -vv me@myserver

Does anyone know what this means? Anyone with more experience know what could be happening here and how to fix?

The problem is this Citrix dll:

Process 29820 loaded C:\Program Files (x86)\Citrix\ICA Client\epclient64.dll

It is related to anti-screenshot and anti-keylogging (see https://www.reddit.com/r/Citrix/comments/kqah4o/ssh_on_my_private_computer_loads_citrixica/).

I uninstalled Citrix and now ssh is working again.

And also Greenshot is working again!