GUP Proxy Tool - Threat Group Cards: A Threat Actor Encyclopedia Archived: 2026-04-05 19:50:35 UTC Home > List all groups > List all tools > List all groups using tool GUP Proxy Tool Tool: GUP Proxy Tool Names GUP Proxy Tool Category Malware Type Backdoor Description (Proofpoint) The GUP command and control proxy tool may impersonate the name of a piece of legitimate opensource software available at wingup[.]org, which is used by Notepad++. In historic campaigns by APT adversaries, legitimate GUP.exe versions were utilized that were digitally signed by Notepad++. In this campaign, files appeared to impersonate the GUP.exe file name rather than being a legitimate signed binary. The function of this tool is to set up a TCP listener on a localhost, receive encoded data via requests from the SodomNormal localhost module, and to forward this data to the command and control IP via HTTP. The GUP Proxy Tool has a hardcoded configuration which is included as both strings and integers. Information Malpedia Last change to this tool card: 24 April 2021 Download this tool card in JSON format All groups using tool GUP Proxy Tool Changed Name Country Observed APT groups   LookBack, TA410 [Unknown] 2019-Feb 2022   https://apt.etda.or.th/cgi-bin/listgroups.cgi?u=bbb65fa6-b7ba-4d24-9b9d-5e189dcba544 Page 1 of 2 1 group listed (1 APT, 0 other, 0 unknown) Source: https://apt.etda.or.th/cgi-bin/listgroups.cgi?u=bbb65fa6-b7ba-4d24-9b9d-5e189dcba544 https://apt.etda.or.th/cgi-bin/listgroups.cgi?u=bbb65fa6-b7ba-4d24-9b9d-5e189dcba544 Page 2 of 2