Resubmissions

15/04/2026, 18:51

260415-xhssxsgx3j10

15/04/2026, 18:46

260415-xepbbsa19110

Analysis

  • user interaction
    yes
  • max time kernel
    150s
  • max time network
    151s
  • platform
    windows10-ltsc_2021_x64
  • resource
    win10ltsc2021-20260130-en
  • resource tags

    arch:x64arch:x86image:win10ltsc2021-20260130-enlocale:en-usos:windows10-ltsc_2021-x64systemwindows
  • submitted
    15/04/2026, 18:46

General

  • Target
    MasonClient.exe
  • Size 49KB
  • Sample260415-xepbbsa191
  • SHA256 4b361c4f5b2dae48be44036c2d484244a678c0fa58bc0d3bd38bf2a9564ded72
  • MD5 SHA1 SHA512 SSDEEP TLSH

Malware Config

Extracted

Family
  • neptunerat

C2
  • 4oyai0loeu.localto.net:8822

Signatures

  • Family: NeptuneRAT, MasonRAT

    NeptuneRAT aka MasonRAT is a trojan written in C#.

  • Detects NeptuneRAT stealer 2 IoCs
  • Contacts third-party web service commonly abused for C2 1 TTPs 4 IoCs

    Legitimate web (hosting) services can be abused by malware authors to host malware or C2s.

  • Sets desktop wallpaper using registry 2 TTPs 1 IoCs
  • Drops file in Windows directory 1 IoCs
  • Browser Information Discovery 1 TTPs

    Enumerate browser information.

  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s).

  • System Time Discovery 1 TTPs 1 IoCs

    Adversary may gather the system time and/or time zone settings from a local or remote system.

  • Checks processor information in registry 2 TTPs 2 IoCs

    Processor information is often read in order to detect sandboxing environments.

  • Enumerates system info in registry 2 TTPs 3 IoCs
  • Modifies data under HKEY_USERS 2 IoCs
  • Modifies registry class 1 IoCs
  • Suspicious behavior: NtCreateUserProcessBlockNonMicrosoftBinary 4 IoCs
  • Suspicious use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of FindShellTrayWindow 2 IoCs
  • Suspicious use of WriteProcessMemory 39 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\MasonClient.exe
    "C:\Users\Admin\AppData\Local\Temp\MasonClient.exe"
    1⤵
    • Sets desktop wallpaper using registry
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:3804
    • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
      "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --single-argument C:\Users\Admin\Desktop\How To Decrypt My Files.html
      2⤵
      • Drops file in Windows directory
      • Checks processor information in registry
      • Enumerates system info in registry
      • Modifies data under HKEY_USERS
      • Modifies registry class
      • Suspicious behavior: NtCreateUserProcessBlockNonMicrosoftBinary
      • Suspicious use of FindShellTrayWindow
      • Suspicious use of WriteProcessMemory
      PID:2636
      • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
        "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=crashpad-handler "--user-data-dir=C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data" /prefetch:4 --monitor-self-annotation=ptype=crashpad-handler "--database=C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Crashpad" --annotation=IsOfficialBuild=1 --annotation=channel= --annotation=chromium-version=139.0.7258.155 "--annotation=exe=C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --annotation=plat=Win64 --annotation=prod=Edge --annotation=ver=139.0.3405.125 --initial-client-data=0x2ec,0x2f0,0x2f4,0x2e8,0x314,0x7ff85690c188,0x7ff85690c194,0x7ff85690c1a0
        3⤵
          PID:2356
        • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
          "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=network.mojom.NetworkService --lang=en-US --service-sandbox-type=none --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=2008,i,12714359500872313031,16834197708204331792,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=4048 /prefetch:3
          3⤵
          • System Time Discovery
          PID:1480
        • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
          "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=gpu-process --no-pre-read-main-dll --force-high-res-timeticks=disabled --gpu-preferences=SAAAAAAAAADgAAAIAAAAAAAAAAAAAGAAAQAAAAAAAAAEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQAAAAAAAAABAAAAAAAAAACAAAAAAAAAAIAAAAAAAAAA== --always-read-main-dll --metrics-shmem-handle=1820,i,14370445229942874181,16196421491059200666,262144 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=3784 /prefetch:2
          3⤵
            PID:400
          • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
            "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=storage.mojom.StorageService --lang=en-US --service-sandbox-type=service --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=2384,i,16875857362192449129,8330572780487567492,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=4140 /prefetch:8
            3⤵
              PID:4576
            • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
              "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=renderer --pdf-upsell-enabled --force-high-res-timeticks=disabled --video-capture-use-gpu-memory-buffer --lang=en-US --js-flags=--ms-user-locale= --device-scale-factor=1 --num-raster-threads=4 --enable-main-frame-before-activation --renderer-client-id=6 --always-read-main-dll --metrics-shmem-handle=3112,i,5048830555051042839,3344284576156212274,2097152 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=4188 /prefetch:1
              3⤵
                PID:1064
              • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=renderer --pdf-upsell-enabled --force-high-res-timeticks=disabled --video-capture-use-gpu-memory-buffer --lang=en-US --js-flags=--ms-user-locale= --device-scale-factor=1 --num-raster-threads=4 --enable-main-frame-before-activation --renderer-client-id=5 --always-read-main-dll --metrics-shmem-handle=3116,i,6836187165429781493,13686766900967781921,2097152 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=4192 /prefetch:1
                3⤵
                  PID:4792
                • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                  "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=renderer --pdf-upsell-enabled --force-high-res-timeticks=disabled --video-capture-use-gpu-memory-buffer --lang=en-US --js-flags=--ms-user-locale= --device-scale-factor=1 --num-raster-threads=4 --enable-main-frame-before-activation --renderer-client-id=7 --always-read-main-dll --metrics-shmem-handle=3280,i,11646415111946873720,11321736642080684033,2097152 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=4204 /prefetch:1
                  3⤵
                    PID:1180
                  • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                    "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=renderer --extension-process --renderer-sub-type=extension --pdf-upsell-enabled --force-high-res-timeticks=disabled --video-capture-use-gpu-memory-buffer --lang=en-US --js-flags=--ms-user-locale= --device-scale-factor=1 --num-raster-threads=4 --enable-main-frame-before-activation --renderer-client-id=8 --always-read-main-dll --metrics-shmem-handle=3296,i,16826615790971241658,14558382322313913839,2097152 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=4220 /prefetch:2
                    3⤵
                      PID:3528
                    • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                      "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=PooledProcess2 --lang=en-US --service-sandbox-type=utility --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=5092,i,14797826183337094887,13885036602977806197,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=5012 /prefetch:8
                      3⤵
                        PID:4984
                      • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                        "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=PooledProcess2 --lang=en-US --service-sandbox-type=utility --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=5216,i,3144650039388546578,4413852623956450371,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=5016 /prefetch:8
                        3⤵
                          PID:3604
                        • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                          "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=asset_store.mojom.AssetStoreService --lang=en-US --service-sandbox-type=asset_store_service --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=5012,i,6841259213074719375,12989086030943981221,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=5304 /prefetch:8
                          3⤵
                            PID:1640
                          • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                            "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=entity_extraction_service.mojom.Extractor --lang=en-US --service-sandbox-type=entity_extraction --onnx-enabled-for-ee --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=5172,i,14592965545622487884,11113290656537197703,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=5256 /prefetch:8
                            3⤵
                              PID:2400
                            • C:\Program Files (x86)\Microsoft\Edge\Application\139.0.3405.125\identity_helper.exe
                              "C:\Program Files (x86)\Microsoft\Edge\Application\139.0.3405.125\identity_helper.exe" --type=utility --utility-sub-type=winrt_app_id.mojom.WinrtAppIdService --lang=en-US --service-sandbox-type=none --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=5724,i,4710949265636184665,1324382426555522433,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=5740 /prefetch:8
                              3⤵
                                PID:2472
                              • C:\Program Files (x86)\Microsoft\Edge\Application\139.0.3405.125\identity_helper.exe
                                "C:\Program Files (x86)\Microsoft\Edge\Application\139.0.3405.125\identity_helper.exe" --type=utility --utility-sub-type=winrt_app_id.mojom.WinrtAppIdService --lang=en-US --service-sandbox-type=none --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=5724,i,4710949265636184665,1324382426555522433,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=5740 /prefetch:8
                                3⤵
                                  PID:2480
                                • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                                  "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=unzip.mojom.Unzipper --lang=en-US --service-sandbox-type=service --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=5976,i,13391682700683914902,11109778525336029143,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=5984 /prefetch:8
                                  3⤵
                                    PID:564
                                  • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                                    "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=unzip.mojom.Unzipper --lang=en-US --service-sandbox-type=service --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=5896,i,5742549255443937191,17844298801321210785,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=5904 /prefetch:8
                                    3⤵
                                      PID:5048
                                    • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                                      "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=unzip.mojom.Unzipper --lang=en-US --service-sandbox-type=service --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=6060,i,11939211492807613296,14646985818224307173,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=6188 /prefetch:8
                                      3⤵
                                        PID:1968
                                      • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                                        "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=unzip.mojom.Unzipper --lang=en-US --service-sandbox-type=service --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=5996,i,2419266032833576560,7973590830806853952,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=6360 /prefetch:8
                                        3⤵
                                          PID:340
                                        • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
                                          "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=PooledProcess2 --lang=en-US --service-sandbox-type=utility --force-high-res-timeticks=disabled --always-read-main-dll --metrics-shmem-handle=5900,i,8948557598248550289,4262031997100811422,524288 --field-trial-handle=3792,i,12501251775949123675,2311320099273801838,262144 --variations-seed-version --mojo-platform-channel-handle=5884 /prefetch:8
                                          3⤵
                                            PID:3096
                                      • C:\Program Files (x86)\Microsoft\Edge\Application\139.0.3405.125\elevation_service.exe
                                        "C:\Program Files (x86)\Microsoft\Edge\Application\139.0.3405.125\elevation_service.exe"
                                        1⤵
                                          PID:3544

                                        Network

                                              MITRE ATT&CK Enterprise v16

                                              Replay Monitor

                                              Loading Replay Monitor...

                                              Downloads

                                              CrashpadMetrics-active.pma

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\CrashpadMetrics-active.pma
                                              • Size 16KB
                                              • SHA256 fde3b41a5711362d7f3df7d71563d5eb6cc679bae7f80f74afcdf81dbc09eafd
                                              • MD5 SHA1 SHA512 SSDEEP TLSH

                                              settings.dat

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Crashpad\settings.dat
                                              • Size 280B
                                              • SHA256 b5ec46fa431794c7d59f9fc0057e1e3e3b1af4e12dff7d68bc94d155efc6ffec
                                              • MD5 SHA1 SHA512 TLSH

                                              settings.dat

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Crashpad\settings.dat
                                              • Size 280B
                                              • SHA256 a9b4b644a6d0e658838d87f47f679cce5368e7cec46064a4bf3d8d2cb1bb1c32
                                              • MD5 SHA1 SHA512 TLSH

                                              6f5806cb-fb1a-4e23-9c1b-9597ad14aaa8.tmp

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Default\6f5806cb-fb1a-4e23-9c1b-9597ad14aaa8.tmp
                                              • Size 106KB
                                              • SHA256 eb2fd7422436fff93f6be09df3294b26cdb7afd18e6aa94dcdc0f208db78b2ed
                                              • MD5 SHA1 SHA512 SSDEEP TLSH

                                              SiteList-Enterprise.json

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Default\DualEngine\SiteList-Enterprise.json
                                              • Size 2B
                                              • SHA256 44136fa355b3678a1146ad16f7e8649e94fb4fc21fe77e8310c060f61caaff8a
                                              • MD5 SHA1 SHA512

                                              Edge Profile.ico

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Default\Edge Profile.ico
                                              • Size 70KB
                                              • SHA256 31a226211c491e1b0832d4cd3cf34d97165e24a7ce4ec655259cd188f3a2bd88
                                              • MD5 SHA1 SHA512 SSDEEP TLSH

                                              SCT Auditing Pending Reports

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Default\Network\SCT Auditing Pending Reports
                                              • Size 2B
                                              • SHA256 4f53cda18c2baa0c0354bb5f9a3ecbe5ed12ab4d8e11ba873c2f11161202b945
                                              • MD5 SHA1 SHA512

                                              sync_diagnostic.log

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Default\Sync Data\Logs\sync_diagnostic.log
                                              • Size 4KB
                                              • SHA256 ff5d48ba38d17e8eae5c6c0b29524ea275f9748b88479320898e140385814462
                                              • MD5 SHA1 SHA512 SSDEEP TLSH

                                              CURRENT

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Default\Sync Extension Settings\dcaajljecejllikfgbhjdgeognacjkkp\CURRENT
                                              • Size 16B
                                              • SHA256 0f1bad70c7bd1e0a69562853ec529355462fcd0423263a3d39d6d0d70b780443
                                              • MD5 SHA1 SHA512

                                              MANIFEST-000001

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Default\Sync Extension Settings\dcaajljecejllikfgbhjdgeognacjkkp\MANIFEST-000001
                                              • Size 41B
                                              • SHA256 f9d31b278e215eb0d0e9cd709edfa037e828f36214ab7906f612160fead4b2b4
                                              • MD5 SHA1 SHA512

                                              Local State

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Local State
                                              • Size 8KB
                                              • SHA256 a1d95b958615c9685b7b4deb835ddb93735a14614daf7c54909474b8dd1e2a78
                                              • MD5 SHA1 SHA512 SSDEEP TLSH

                                              Local State

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\Edge\User Data\Local State
                                              • Size 8KB
                                              • SHA256 4f872775cf280d66d0afa718a02e9ec0e2c19043f88b1f765ddc1fe8fe0ffecf
                                              • MD5 SHA1 SHA512 SSDEEP TLSH

                                              5a2a7058cf8d1e56c20e6b19a7c48eb2386d141b.tbres

                                              • Path C:\Users\Admin\AppData\Local\Microsoft\TokenBroker\Cache\5a2a7058cf8d1e56c20e6b19a7c48eb2386d141b.tbres
                                              • Size 2KB
                                              • SHA256 4ffc8655cb507d62bb2321f6db279f8e2c81f8b9f2d3e1802e80ec206a38d651
                                              • MD5 SHA1 SHA512 TLSH

                                              8837be40-4206-4826-9740-42ac9b03c27e.tmp

                                              • Path C:\Users\Admin\AppData\Local\Temp\8837be40-4206-4826-9740-42ac9b03c27e.tmp
                                              • Size 1B
                                              • SHA256 cdb4ee2aea69cc6a83331bbe96dc2caa9a299d21329efb0336fc02a82e1839a8
                                              • MD5 SHA1 SHA512

                                              content_new.js

                                              • Path C:\Users\Admin\AppData\Local\Temp\scoped_dir2636_1427334112\CRX_INSTALL\content_new.js
                                              • Size 10KB
                                              • SHA256 d4aa4602a1590a4b8a1bce8b8d670264c9fb532adc97a72bc10c43343650385a
                                              • MD5 SHA1 SHA512 SSDEEP TLSH

                                              messages.json

                                              • Path C:\Users\Admin\AppData\Local\Temp\scoped_dir2636_1534388484\CRX_INSTALL\_locales\en\messages.json
                                              • Size 851B
                                              • SHA256 6895648577286002f1dc9c3366f558484eb7020d52bbf64a296406e61d09599c
                                              • MD5 SHA1 SHA512 TLSH

                                              How To Decrypt My Files.html

                                              • Path C:\Users\Admin\Desktop\How To Decrypt My Files.html
                                              • Size 724B
                                              • SHA256 fd0bc4f04864dbd7d89c8eb185663bce7f16ad4800fa89f4a0adb640ae5f5f73
                                              • MD5 SHA1 SHA512 TLSH

                                              NTUSER.DAT{53b39e88-18c4-11ea-a811-000d3aa4692b}.TMContainer00000000000000000001.regtrans-ms.ENC

                                              • Path C:\Users\Admin\NTUSER.DAT{53b39e88-18c4-11ea-a811-000d3aa4692b}.TMContainer00000000000000000001.regtrans-ms.ENC
                                              • Size 16B
                                              • SHA256 34df3c1838f4ffd7be5042749a68f588f51bdc076ffa0a36f94be6e44a443b1d
                                              • MD5 SHA1 SHA512

                                              memory/3804-0-0x0000000000730000-0x0000000000742000-memory.dmp

                                              memory/3804-16-0x0000000000DB0000-0x0000000000DBC000-memory.dmp

                                              memory/3804-3-0x000000001B5D0000-0x000000001B5E0000-memory.dmp

                                              memory/3804-2-0x0000000000FE0000-0x0000000000FEC000-memory.dmp

                                              memory/3804-1-0x000000001B5D0000-0x000000001B5E0000-memory.dmp