Ceplin Command Identifier

Identifier / Programs / Windows

zipfldr.dll

Compressed (zipped) Folders file version info (xCyclopedia)

LOLBAS Execute 1 ATT&CK technique 2 documented commands 2 known copies with hashes

Opens the identifier with your command. It is read in your browser and sent nowhere.

How zipfldr.dll is abused

documented by LOLBAS

Execute T1218.011 System Binary Proxy Execution: Rundll32

Run by rundll32.exe: zipfldr.dll,routethecall

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

2 documented commands

from LOLBAS, each read by the identifier

Execute T1218.011 System Binary Proxy Execution: Rundll32 User privileges

Launch an executable payload by calling RouteTheCall.

rundll32.exe zipfldr.dll,RouteTheCall {PATH:.exe}
Identify

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

Execute T1218.011 System Binary Proxy Execution: Rundll32 User privileges

Launch an executable payload by calling RouteTheCall (obfuscated).

rundll32.exe zipfldr.dll,RouteTheCall file://^C^:^/^W^i^n^d^o^w^s^/^s^y^s^t^e^m^3^2^/^c^a^l^c^.^e^x^e
Identify

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

All 2 commands the identifier reads trip a Sigma process-creation rule. These commands and their descriptions are from LOLBAS’s entry for zipfldr.dll, by LOLBAS Team, 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 zipfldr.dll. The identifier reads each 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
T1218.011System Binary Proxy Execution: Rundll32

Is it the real zipfldr.dll?

file version info and known copies
Installed inC:\Windows\system32\
C:\Windows\SysWOW64\
Signed byMicrosoft Windows
ProductMicrosoft Windows Operating System, Microsoft Corporation
DescriptionCompressed (zipped) Folders

2 known copies

10.0.19041.1 (WinBuild.160101.0800) · C:\Windows\SysWOW64\zipfldr.dll · signed by Microsoft Windows

6cc4b493b39999303124d8410bc3f209adf4de96181483a0d28aa806707f43c9

10.0.19041.1 (WinBuild.160101.0800) · C:\Windows\system32\zipfldr.dll · signed by Microsoft Windows

c771833cab450839f5acadcbdbc42a6f1afa118013d87c6f2adc3c412512bd0a

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.