Identifier / Programs / Windows

dfsvc.exe

ClickOnce file version info (xCyclopedia)

LOLBAS AWL Bypass 1 ATT&CK technique 1 documented command 2 known copies with hashes

How dfsvc.exe is abused

documented by LOLBAS

AWL Bypass T1127.002 Trusted Developer Utilities Proxy Execution: ClickOnce

Run by rundll32.exe: dfshim.dll,shopenverbapplication

Each abuse is LOLBAS's category and the options and words it uses; the full write-up is on LOLBAS's page for dfsvc.exe.

1 documented command

from LOLBAS, each read by the identifier

AWL Bypass T1127.002 Trusted Developer Utilities Proxy Execution: ClickOnce User privileges

Executes click-once-application from Url (trampoline for Dfsvc.exe, DotNet ClickOnce host)

rundll32.exe dfshim.dll,ShOpenVerbApplication {REMOTEURL}

Identify

Trips 1 Sigma rule: mediumPotentially Suspicious Rundll32 Activity by juju4, Jonhnathan Ribeiro, oscd.community, Nasreddine Bencherchali (Nextron Systems)

The command the identifier reads trips a Sigma process-creation rule. These commands and their descriptions are from LOLBAS’s entry for dfsvc.exe, by Oddvar Moe, at commit 2056cb766250 of 2026-09-26, under the GPL-3.0 and LOLBAS’s notice, with no warranty. Changed: Markdown is shown formatted. The source is in lolbas-gtfobins-commands.json.gz, and the full entry is on LOLBAS’s page for dfsvc.exe. The identifier reads it with LOLBAS’s placeholders filled in: a URL as https://example.com/file, a share as \\192.0.2.10\share\file, a path as C:\Data\file and a command as calc.exe.

What detects it

Sigma process creation rules

T1127.002Trusted Developer Utilities Proxy Execution: ClickOnce

Is it the real dfsvc.exe?

file version info and known copies

Installed inC:\Windows\Microsoft.NET\Framework\v4.0.30319\

Signed byMicrosoft Windows

ProductMicrosoft .NET Framework, Microsoft Corporation

DescriptionClickOnce

2 known copies

4.8.4161.0 built by: NET48REL1 · C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\dfsvc.exe · signed by Microsoft Windows

584986978cede231bd748955f8a3777060fccb4b942939476891db25a37b3f3c

4.8.4084.0 built by: NET48REL1 · C:\Windows\Microsoft.NET\Framework\v4.0.30319\dfsvc.exe · signed by Microsoft Windows

375a75016c4feddb43c7ebfe9e78670c7c9ff0753cd8ea59e4cf601ee8624659

From the file’s version info and the copies recorded by xCyclopedia (MIT). A copy in another folder, signed by someone else or with another hash is not necessarily malicious, but it is worth a closer look. In Ceplin, "<sha256>".whatis() says which known copy a hash is.