comsvcs.dll

COM+ Services file version info (xCyclopedia)

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

How comsvcs.dll is abused

documented by LOLBAS

Dump T1003.001 OS Credential Dumping: LSASS Memory

Run by rundll32.exe: minidump full

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

1 documented command

from LOLBAS, each read by the identifier

Dump T1003.001 OS Credential Dumping: LSASS Memory SYSTEM privileges

Calls the MiniDump exported function of comsvcs.dll, which in turns calls MiniDumpWriteDump.

rundll32 C:\windows\system32\comsvcs.dll MiniDump {LSASS_PID} dump.bin full

Identify

Trips 2 Sigma rules: highProcess Memory Dump Via Comsvcs.DLL by Florian Roth (Nextron Systems), Modexp, Nasreddine Bencherchali (Nextron Systems), Swachchhanda Shrawan Poudel (Nextron Systems); 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 comsvcs.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 comsvcs.dll. 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

T1003.001OS Credential Dumping: LSASS Memory

Is it the real comsvcs.dll?

file version info and known copies

Installed inC:\Windows\system32\
C:\Windows\SysWOW64\

Signed byMicrosoft Windows

ProductMicrosoft Windows Operating System, Microsoft Corporation

DescriptionCOM+ Services

2 known copies

2001.12.10941.16384 (WinBuild.160101.0800) · C:\Windows\system32\comsvcs.dll · signed by Microsoft Windows

1aea658899018fb370c39412ba62e3e8e8fd7a636657593530bd67005b3754b7

2001.12.10941.16384 (WinBuild.160101.0800) · C:\Windows\SysWOW64\comsvcs.dll · signed by Microsoft Windows

e0b9fca1f03cc9d196a78339a0ccbbba32bea78a0fe645257d32310b5ad4e273

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.