Red UAC Prompt On Windows XP Machines

[CCB-IT]

We are using UltraVNC 1.9.6.1 deployed via VNCScan. I don't know why, but for the vast majority of our environment it has worked fine. However, recently several of our machines have begun generating a Red UAC prompt. This is very odd as this has only occured on our Windows XP machines. All Windows 7 machines have not had this problem. Here is the prompt:



Nothing has helped. I have uninstalled, and reinstalled it multiple times. I have tried the various options listed in this post:

http://forum.ultravnc.info/viewtopic.ph ... 510#p90474

This is driving me insane. It says that it is in Application mode, but I can verify that the Service is installed and working. The only thing I haven't tried is installing the program manually. But why would that be any different? The same deployment works for 98% of our systems, and none of the affected PCs are any different to my knowledge. Here is a copy of our Ultravnc.ini file, minus all security information:

Code: Select all

[admin]
PortNumber=5900
AutoPortSelect=0
IdleTimeout=3600
HTTPPortNumber=0
RemoveWallpaper=0
DisableInterfaceEffects=0
RemoveBackground=0
UseHooks=0
PollScreen=0
FilterEvents=0
AcceptClipboard=0
AcceptKeyboard=0
inputs_chkAcceptPointerEvents=0
AffectScreenSaver=0
DisableLocalInputs=0
SendClipboard=1
NeverShared=0
AlwaysShared=1
DisableTrayIcon=1
MSLogonRequired=0
NewMSLogon=0
AllowShutdown=0
AllowProperties=0
QuerySetting=2
ConnectPriority=0
DSMPlugin=SecureVNCPlugin.dsm
UseDSMPlugin=1
UseRegistry=0
DebugMode=0
Avilog=0
kickrdp=0
service_commandline=
DebugLevel=8
LoopbackOnly=0
AllowLoopback=0
AuthRequired=1
AllowEditClients=1
FileTransferEnabled=1
FTUserImpersonation=1
BlankMonitorEnabled=1
BlankInputsOnly=0
DefaultScale=1
CaptureAlphaBlending=1
BlackAlphaBlending=0
SocketConnect=1
HTTPConnect=0
XDMCPConnect=1
RemoveAero=0
QueryTimeout=0
QueryAccept=0
QueryIfNoLogon=0
primary=1
secondary=1
InputsEnabled=1
LockSetting=0
LocalInputsDisabled=0
EnableJapInput=0
FileTransferTimeout=30
dummy=0
SC_PROMPT=0
SC_AUTORECON=0
DSMPluginConfig=
secundary=0
[poll]
TurboMode=0
PollUnderCursor=1
PollForeground=1
PollFullScreen=1
OnlyPollConsole=0
OnlyPollOnEvent=0
EnableDriver=1
EnableHook=1
EnableVirtual=0
SingleWindow=0
SingleWindowName=
UseHooks=1
FileTransfersEnabled=1
FTUserImpersonation=1
[presets]
preset1=
preset1D=
preset1ID=
preset2=
preset2D=
preset2ID=
preset3=
preset3D=
preset3ID=

As you can see we are using the normal port 5900 with the SecureVNC plugin. Any idea what could be wrong?

[B]

Maybe Rudi's response at https://forum.ultravnc.net/viewtopic.php?f=64&t=28906 would be helpful?

[CCB-IT]

I'm afraid I don't follow. What Rudi posted was about initiating a reverse connection. This is just a normal connection. From Viewer to server on a local network. I've also tried setting Debug to 1 and the level to 12 but I'm not getting any log info from it. Help!

[B]

I was hoping something in that thread would shed light on your situation, since Bonji was getting a similar error.

Stepping back a second, is there in fact a UAC event happening when this red screen is generated in the viewer? When the local user accepts the UAC prompt, does the session continue properly?

Are you using MSLogon?

Sorry I don't have any good advice for you -- YY, Rudi, redge, supercoe, you folks out there?

And wait a second -- VNCScan's a commercial product -- can't you try his support forums? http://bozteck.com/vncscan/bozteck-support-center.html

[CCB-IT]

No problem, it was worth looking into. I'm afraid there is no UAC event happening when I try to log into the users machine. As mentioned, these are Windows XP machines, so UAC doesn't even exist! We are not using MSLogon, only the built in password.

Agreed on VNCScan, but I don't know if they will have anything useful to contribute. The deployment from VNCScan works fine on this and every other machine runs fine. It's just a few machines that its installed on that are generating this UAC error. I will check around their forums though. Also, to eliminate it as a culprit I'm going to do a manual install on a users machine and see how it runs. If it runs fine then something likely is amiss with VNCScans deployment. If it does the same then I'm at a loss again.

[CCB-IT]

Welp, I have figured it out! Turns out it was VNCScan. Though I'm still not sure how it was working on some and not others. VNCScan installed the VNC service as winvnc. Whereas UVNC installs it as uvnc_service. All I had to do was delete the Winvnc service, and install the uvnc service. Once I did that it worked just fine. No clue what happened to cause this. But its fixed now!

[B]

Beautiful. Thank you so much for following up to let us know. I would guess that VNCScan supports multiple different VNC engines and got confused at some point as to which engine it was installing for you.