TWAIN error-- Remember seeing this variant in the past..May be this time its in a new dimension.. This kind of malware doesn't usually arrive as a single process. They are usually accompanied by their companions who help them. Are you able to track the backbone for the error using process explorer ? Any other associated packed process ?. Usually the malware triggers this error via Microsoft rundll32.exe OR if you see the legitimate process named "twunk_32.exe" is involved then hover the mouse over this process in process explorer and press ctrl+d to list the associated dlls. One of them might be driving this behaviour/error.
Alternatively use the command prompt and trigger (tasklist /m /fi “imagename eq rundll32.exe”) in the command prompt. This will help identifying any malware libraries abusing the rundll32.exe. Check for any anomalies or suspicious dlls in the result.
If you did find any suspicious/wierd file then ,As stated by forum members please send the file to Symantec for analysis or upload it to any SANDBOX analyzer such as virustotal.com or virscan.org and see what other A/V engine suspects on the sample.