silverrat | 572b99caeb57f1999a3c7ec8ebea458cbde138bec44ed5531b8877249a1f594f

General

Target

Astri.exe
Size

43KB
MD5

2f208058419a16ca3fa3574867071b4a
SHA1

ebaf2a437720c0d5915fee4f2943d35ff70d7258
SHA256

572b99caeb57f1999a3c7ec8ebea458cbde138bec44ed5531b8877249a1f594f
SHA512

e1c720cc30303303d7d850e5d72fce2d8e1274739b46516e684ea2761446fe090b35e58c4aa1e7405c1908e0dc614767cec3b749b262e5dde6370dfc02427967
SSDEEP

768:aR8c2Sev8VX/Ol6IoZmLPHBm7p4A6+HWbxk5XORULQI9PNGUz1QB6Sj/lo:aR8c2SeMwt5Jml5bWOOGsI94I1Qo4/lo

Score

10^/10

silverrat defense_evasion execution persistence trojan

Malware Config

Extracted

Family

silverrat

Version

1.0.0.0

C2

american-designed.gl.at.ply.gg:50767

Mutex

lAxDBRhAFu

Attributes

certificate
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
decrypted_key
-|S.S.S|-
key
yy6zDjAUmbB09pKvo5Hhug==
key_x509
b0FGeVZNcFRMWVloVHR6Z0VESU5RdlpZUmxZbUFE
reconnect_delay
1
server_signature
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

Signatures

SilverRat
SilverRat is trojan written in C#.
trojan silverrat
Silverrat family
silverrat

Sets file to hidden 1 TTPs 2 IoCs

Modifies file attributes to stop it showing in Explorer etc.

defense_evasion

Hidden Files and Directories

T1564.001

pid	Process
5188	attrib.exe
4528	attrib.exe

Checks computer location settings 2 TTPs 2 IoCs

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

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key value queried	\REGISTRY\USER\S-1-5-21-1062200478-553497403-3857448183-1000\Control Panel\International\Geo\Nation	$77syshostreq.exe
Key value queried	\REGISTRY\USER\S-1-5-21-1062200478-553497403-3857448183-1000\Control Panel\International\Geo\Nation	Astri.exe

Executes dropped EXE 1 IoCs

pid	Process
464	$77syshostreq.exe

Adds Run key to start application 2 TTPs 1 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\ = "\"C:\\Users\\Admin\\syshoster\\$77syshostreq.exe\""	Astri.exe

Command and Scripting Interpreter: PowerShell 1 TTPs 1 IoCs

Using powershell.exe command.

execution

PowerShell

T1059.001

pid	Process
3516	powershell.exe

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

System Information Discovery
T1082

Delays execution with timeout.exe 1 IoCs

defense_evasion

pid	Process
5076	timeout.exe

Scheduled Task/Job: Scheduled Task 1 TTPs 2 IoCs

Schtasks is often used by malware for persistence or to perform post-infection execution.

persistence execution

Scheduled Task

T1053.005

pid	Process
4012	schtasks.exe
3428	schtasks.exe

Suspicious behavior: EnumeratesProcesses 24 IoCs

pid	Process
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
5204	Astri.exe
464	$77syshostreq.exe
3516	powershell.exe
3516	powershell.exe

Suspicious use of AdjustPrivilegeToken 6 IoCs

description	pid	Process
Token: SeBackupPrivilege	5388	vssvc.exe
Token: SeRestorePrivilege	5388	vssvc.exe
Token: SeAuditPrivilege	5388	vssvc.exe
Token: SeDebugPrivilege	5204	Astri.exe
Token: SeDebugPrivilege	464	$77syshostreq.exe
Token: SeDebugPrivilege	3516	powershell.exe

Suspicious use of SetWindowsHookEx 1 IoCs

pid	Process
464	$77syshostreq.exe

Suspicious use of WriteProcessMemory 20 IoCs

description	pid	Process	procid_target
PID 5204 wrote to memory of 5188	5204	Astri.exe	93
PID 5204 wrote to memory of 5188	5204	Astri.exe	93
PID 5204 wrote to memory of 4528	5204	Astri.exe	95
PID 5204 wrote to memory of 4528	5204	Astri.exe	95
PID 5204 wrote to memory of 4548	5204	Astri.exe	98
PID 5204 wrote to memory of 4548	5204	Astri.exe	98
PID 4548 wrote to memory of 5076	4548	cmd.exe	100
PID 4548 wrote to memory of 5076	4548	cmd.exe	100
PID 4548 wrote to memory of 464	4548	cmd.exe	101
PID 4548 wrote to memory of 464	4548	cmd.exe	101
PID 464 wrote to memory of 1176	464	$77syshostreq.exe	103
PID 464 wrote to memory of 1176	464	$77syshostreq.exe	103
PID 464 wrote to memory of 3428	464	$77syshostreq.exe	105
PID 464 wrote to memory of 3428	464	$77syshostreq.exe	105
PID 464 wrote to memory of 4272	464	$77syshostreq.exe	107
PID 464 wrote to memory of 4272	464	$77syshostreq.exe	107
PID 464 wrote to memory of 3516	464	$77syshostreq.exe	109
PID 464 wrote to memory of 3516	464	$77syshostreq.exe	109
PID 464 wrote to memory of 4012	464	$77syshostreq.exe	111
PID 464 wrote to memory of 4012	464	$77syshostreq.exe	111

Uses Task Scheduler COM API 1 TTPs
The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.
persistence

Query Registry
T1012
Uses Volume Shadow Copy service COM API
The Volume Shadow Copy service is used to manage backups/snapshots.
ransomware

Views/modifies file attributes 1 TTPs 2 IoCs

defense_evasion

Hidden Files and Directories

T1564.001

pid	Process
5188	attrib.exe
4528	attrib.exe

C:\Users\Admin\AppData\Local\Temp\Astri.exe
"C:\Users\Admin\AppData\Local\Temp\Astri.exe"
1⤵
- Checks computer location settings
- Adds Run key to start application
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:5204
- C:\Windows\System32\attrib.exe
  "C:\Windows\System32\attrib.exe" +s +h "C:\Users\Admin\syshoster"
  2⤵
  - Sets file to hidden
  - Views/modifies file attributes
  PID:5188
- C:\Windows\System32\attrib.exe
  "C:\Windows\System32\attrib.exe" +s +h "C:\Users\Admin\syshoster\$77syshostreq.exe"
  2⤵
  - Sets file to hidden
  - Views/modifies file attributes
  PID:4528
- C:\Windows\system32\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\tmpCE4C.tmp.bat""
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:4548
- - C:\Windows\system32\timeout.exe
    timeout 3
    3⤵
    - Delays execution with timeout.exe
    PID:5076
- - C:\Users\Admin\syshoster\$77syshostreq.exe
    "C:\Users\Admin\syshoster\$77syshostreq.exe"
    3⤵
    - Checks computer location settings
    - Executes dropped EXE
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    - Suspicious use of SetWindowsHookEx
    - Suspicious use of WriteProcessMemory
    PID:464
  - - C:\Windows\SYSTEM32\schtasks.exe
      "schtasks.exe" /query /TN $77syshostreq.exe
      4⤵
      PID:1176
  - - C:\Windows\SYSTEM32\schtasks.exe
      "schtasks.exe" /Create /SC ONCE /TN "$77syshostreq.exe" /TR "C:\Users\Admin\syshoster\$77syshostreq.exe \"\$77syshostreq.exe\" /AsAdmin" /ST 00:01 /IT /F /RL HIGHEST
      4⤵
      Scheduled Task/Job: Scheduled Task
      PID:3428
  - - C:\Windows\SYSTEM32\schtasks.exe
      "schtasks.exe" /query /TN $77syshostreq.exe
      4⤵
      PID:4272
  - - C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" Set-MpPreference -ExclusionExtension exe,bat,dll,ps1;exit
      4⤵
      Command and Scripting Interpreter: PowerShell
      Suspicious behavior: EnumeratesProcesses
      Suspicious use of AdjustPrivilegeToken
      PID:3516
  - - C:\Windows\System32\schtasks.exe
      "C:\Windows\System32\schtasks.exe" /create /sc hourly /mo 1 /tn "syshostreq_Task-HOURLY-01" /tr "%MyFile%" /st 00:00
      4⤵
      Scheduled Task/Job: Scheduled Task
      PID:4012

C:\Windows\system32\vssvc.exe
C:\Windows\system32\vssvc.exe
1⤵
- Suspicious use of AdjustPrivilegeToken
PID:5388

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Command and Scripting Interpreter

1

T1059

PowerShell

1

T1059.001

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Persistence

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Privilege Escalation

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Defense Evasion

Hide Artifacts

2

T1564

Hidden Files and Directories

Modify Registry

Credential Access

Discovery

Query Registry

2

T1012

System Information Discovery

2

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_ovooyejt.ebb.ps1

Filesize
60B

MD5
d17fe0a3f47be24a6453e9ef58c94641

SHA1
6ab83620379fc69f80c0242105ddffd7d98d5d9d

SHA256
96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

SHA512
5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

Download Submit
C:\Users\Admin\AppData\Local\Temp\tmpCE4C.tmp.bat

Filesize
151B

MD5
d0d4f568425418113561e07c83574ec8

SHA1
23ec9ad53ba762f1a23860c4959d230ec1e0bec2

SHA256
553012050887e2c5297acf02320d8dcb396eab9d9c7d17207254e7f80f2da613

SHA512
8c3f64c6ba7c99325af05fb89ab701a1a108586b8d7bf5c24f8333be0c516417d8db9c52c0597644e0150fea6627a6922a85c5960c0df6b5c810917cd22bed02

Download Submit
C:\Users\Admin\syshoster\$77syshostreq.exe

Filesize
43KB

MD5
2f208058419a16ca3fa3574867071b4a

SHA1
ebaf2a437720c0d5915fee4f2943d35ff70d7258

SHA256
572b99caeb57f1999a3c7ec8ebea458cbde138bec44ed5531b8877249a1f594f

SHA512
e1c720cc30303303d7d850e5d72fce2d8e1274739b46516e684ea2761446fe090b35e58c4aa1e7405c1908e0dc614767cec3b749b262e5dde6370dfc02427967

Download Submit
memory/3516-23-0x000002013E600000-0x000002013E622000-memory.dmp

Filesize
136KB

Download
memory/5204-0-0x00007FF814EC3000-0x00007FF814EC5000-memory.dmp

Filesize
8KB

Download
memory/5204-1-0x00000000006F0000-0x0000000000700000-memory.dmp

Filesize
64KB

Download
memory/5204-2-0x00007FF814EC0000-0x00007FF815981000-memory.dmp

Filesize
10.8MB

Download
memory/5204-3-0x00007FF814EC3000-0x00007FF814EC5000-memory.dmp

Filesize
8KB

Download
memory/5204-4-0x00007FF814EC0000-0x00007FF815981000-memory.dmp

Filesize
10.8MB

Download
memory/5204-10-0x00007FF814EC0000-0x00007FF815981000-memory.dmp

Filesize
10.8MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads