Malware Analysis Report

2025-08-05 14:40

Sample ID 250703-f3k55shq3v
Target d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0
SHA256 d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0
Tags
cosmu discovery ransomware worm
score
10/10

Table of Contents

Analysis Overview

MITRE ATT&CK

Enterprise Matrix V16

Analysis: static1

Detonation Overview

Signatures

Analysis: behavioral1

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis Overview

score
10/10

SHA256

d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0

Threat Level: Known bad

The file d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0 was found to be: Known bad.

Malicious Activity Summary

cosmu discovery ransomware worm

Cosmu

Cosmu family

Detects Cosmu payload

Renames multiple (5196) files with added filename extension

Drops file in Program Files directory

System Location Discovery: System Language Discovery

Unsigned PE

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2025-07-03 05:23

Signatures

Unsigned PE

Description Indicator Process Target
N/A N/A N/A N/A

Analysis: behavioral1

Detonation Overview

Submitted

2025-07-03 05:23

Reported

2025-07-03 05:26

Platform

win10v2004-20250502-en

Max time kernel

149s

Max time network

135s

Command Line

"C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe"

Signatures

Cosmu

worm cosmu

Cosmu family

cosmu

Detects Cosmu payload

Description Indicator Process Target
N/A N/A N/A N/A

Renames multiple (5196) files with added filename extension

ransomware

Drops file in Program Files directory

Description Indicator Process Target
File created C:\Program Files\Common Files\microsoft shared\ClickToRun\C2RINTL.et-ee.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Licenses16\VisioPro2019XC2RVL_KMS_ClientC2R-ppd.xrm-ms.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Licenses16\VisioProO365R_SubTrial-pl.xrm-ms.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\PROOF\MSSP7EN.LEX.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Templates\1033\QuizShow.potx.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.NETCore.App\7.0.16\msquic.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Google\Chrome\Application\133.0.6943.60\Locales\id.pak.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\bin\javaws.exe.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\jre\bin\javaw.exe.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\jre\legal\jdk\relaxngcc.md.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\jre\LICENSE.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\MSZIP.DIC.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.27\api-ms-win-crt-math-l1-1-0.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\jre\bin\javafx_font.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\jre\bin\net.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\1033\SLINTL.DLL.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\MEDIA\HAMMER.WAV.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Common Files\microsoft shared\ink\fsdefinitions\main\base_altgr.xml.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App\6.0.27\zh-Hans\System.Windows.Controls.Ribbon.resources.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App\7.0.16\it\PresentationFramework.resources.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jre-1.8\bin\jfr.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Integration\C2RManifest.wordmui.msi.16.en-us.xml.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Licenses16\O365SmallBusPremR_Grace-ul-oob.xrm-ms.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\LivePersonaCard\lpc.win32.bundle.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\sdxs\FA000000018\cardview\lib\native-common\assets\[email protected] C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\7-Zip\Lang\mr.txt.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App\6.0.27\fr\UIAutomationProvider.resources.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App\7.0.16\de\System.Windows.Forms.resources.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jre-1.8\bin\vcruntime140_1.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Licenses16\StandardMSDNR_Retail-ul-oob.xrm-ms.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\sdxs\FA000000042\strings.resjson.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.NETCore.App\8.0.15\System.Security.Principal.Windows.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\jre\lib\security\trusted.libraries.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Licenses16\VisioProO365R_Subscription-ppd.xrm-ms.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\sdxs\FA000000027\assets\Icons\HintBarEllipses.16.GrayF.png.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.NETCore.App\8.0.15\System.ComponentModel.TypeConverter.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App\8.0.15\PresentationFramework.Aero.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\jre\lib\deploy\[email protected] C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\ADDINS\Microsoft Power Query for Excel Integrated\bin\Microsoft.DataIntegration.FuzzyMatching.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Common Files\microsoft shared\ink\fsdefinitions\oskpred\oskpredbase.xml.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.NETCore.App\8.0.15\System.IO.Compression.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\bin\api-ms-win-crt-heap-l1-1-0.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\legal\jdk\pkcs11wrapper.md.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Licenses16\O365ProPlusR_Subscription1-ul-oob.xrm-ms.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.NETCore.App\7.0.16\System.IO.Compression.Brotli.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Licenses16\HomeBusinessR_OEM_Perp3-pl.xrm-ms.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Licenses16\VisioStdVL_KMS_Client-ppd.xrm-ms.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\1033\GR8GALRY.GRA.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\LogoImages\FirstRunLogoSmall.contrast-white_scale-100.png.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Common Files\microsoft shared\ink\Alphabet.xml.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Common Files\System\ado\fr-FR\msader15.dll.mui.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App\7.0.16\es\System.Windows.Controls.Ribbon.resources.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Licenses16\Standard2019R_Grace-ppd.xrm-ms.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\1033\QuickStyles\linesdistinctive.dotx.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Common Files\microsoft shared\VSTO\10.0\1033\VSTOInstallerUI.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App\6.0.27\de\WindowsFormsIntegration.resources.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App\6.0.27\ru\System.Windows.Input.Manipulations.resources.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\bin\jconsole.exe.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Java\jdk-1.8\bin\orbd.exe.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Office16\PAGESIZE\PGLBL054.XML.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Common Files\microsoft shared\ink\pt-PT\tipresx.dll.mui.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\dotnet\shared\Microsoft.NETCore.App\8.0.15\System.Formats.Tar.dll.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Document Themes 16\Theme Fonts\Georgia.xml.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A
File created C:\Program Files\Microsoft Office\root\Licenses16\PowerPointR_OEM_Perp-pl.xrm-ms.tmp C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A

System Location Discovery: System Language Discovery

discovery
Description Indicator Process Target
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe N/A

Processes

C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe

"C:\Users\Admin\AppData\Local\Temp\d1583f19bce89b61829f036bb1856cbc8eb5a912bb6e2672e6d9806edba192b0.exe"

Network

Country Destination Domain Proto
US 8.8.8.8:53 c.pki.goog udp
GB 142.250.179.227:80 c.pki.goog tcp

Files

C:\$Recycle.Bin\S-1-5-21-3951986358-4006919840-1009690842-1000\desktop.ini.tmp

MD5 86be624cba1c5273611c9578d44df08f
SHA1 5fc8672aec0af3588d512b47df4115c57dec4a80
SHA256 351d1b39676f7b94aec037e0aff62502ce27fcb00bc653734745a1c774004bd5
SHA512 45796ce41791ecac7f38f07124af0a4f5638f1303593d59829fdf7db710f5ef6c033525340a2d7a79f2ad5efca3269cce6588eaec8b4ecc7fbb35b4425f4b1ce

C:\e871de07eca81c0a47\2010_x86.log.html.tmp

MD5 66ad297ca6cdf1f3ed0e8379c187edb4
SHA1 810e5408fbf3119410a218867181d541bec331ea
SHA256 55f697c52b1e8b900b1e8e3ce7a43231477866a7b5a1e2fd0c5d9f6d6b5f743e
SHA512 b9ca09a04774b7821254229c56d4091129601d93c4c11b864c7d9b6fe95a5aa8e8e2429b844c479848278a62b5502057009f2b11f645488de54f8e13c308291c

memory/6080-789-0x0000000000400000-0x0000000000407000-memory.dmp