tofsee | 71864f13775192cf8a30f8a9318b224818f6edc52eda6db27b38e549fde0d413

Analysis

max time kernel
144s
max time network
148s
platform
windows7_x64
resource
win7-20221111-en
resource tags

arch:x64arch:x86image:win7-20221111-enlocale:en-usos:windows7-x64system
submitted
07/02/2023, 00:37

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General

Target

file.exe
Size

299KB
MD5

1f374aa76e90385b3697d554fb113906
SHA1

7c70071eee00e510fdeb851df9fe1bd6aafed42e
SHA256

71864f13775192cf8a30f8a9318b224818f6edc52eda6db27b38e549fde0d413
SHA512

bac66f3ddcaa964982ab2f108e4354408a22ed68a322df8ad547cd1d0da3d8120e076747147927be4c63132f289b3cef6be6fa1dc423da951bdc5ee580ce4255
SSDEEP

3072:Hfb6b8akULxbdRmbNPv2i3ClwyKy9gfACW4HluQjiMTE5HyNa5D:/zMLFyJRS4y0AC5FuQj9FNa

Score

10^/10

tofsee evasion persistence trojan

Malware Config

Extracted

Family

tofsee

svartalfheim.top

jotunheim.name

Signatures

Tofsee
Backdoor/botnet which carries out malicious activities based on commands from a C2 server.
trojan tofsee

Windows security bypass 2 TTPs 1 IoCs

evasion trojan

Disabling Security Tools

T1089

Modify Registry

T1112

description	ioc	Process
Set value (int)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows Defender\Exclusions\Paths\C:\Windows\SysWOW64\yrgridiu = "0"	svchost.exe

Creates new service(s) 1 TTPs
persistence

New Service
T1050

Modifies Windows Firewall 1 TTPs 1 IoCs

evasion

Modify Existing Service

T1031

pid	Process
1616	netsh.exe

Sets service image path in 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\yrgridiu\ImagePath = "C:\\Windows\\SysWOW64\\yrgridiu\\gwylcuf.exe"	svchost.exe

Deletes itself 1 IoCs

pid	Process
1804	svchost.exe

Executes dropped EXE 1 IoCs

pid	Process
1500	gwylcuf.exe

Drops file in System32 directory 1 IoCs

description	ioc	Process
File created	C:\Windows\SysWOW64\config\systemprofile:.repos	svchost.exe

Suspicious use of SetThreadContext 1 IoCs

description	pid	Process	procid_target
PID 1500 set thread context of 1804	1500	gwylcuf.exe	41

Launches sc.exe 3 IoCs

Sc.exe is a Windows utlilty to control services on the system.

pid	Process
596	sc.exe
2020	sc.exe
1444	sc.exe

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

System Information Discovery
T1082

Modifies data under HKEY_USERS 2 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\.DEFAULT\Control Panel\Buses	svchost.exe
Set value (data)	\REGISTRY\USER\.DEFAULT\Control Panel\Buses\Config0 = 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	svchost.exe

Suspicious use of WriteProcessMemory 30 IoCs

description	pid	Process	procid_target
PID 1276 wrote to memory of 472	1276	file.exe	28
PID 1276 wrote to memory of 472	1276	file.exe	28
PID 1276 wrote to memory of 472	1276	file.exe	28
PID 1276 wrote to memory of 472	1276	file.exe	28
PID 1276 wrote to memory of 1924	1276	file.exe	30
PID 1276 wrote to memory of 1924	1276	file.exe	30
PID 1276 wrote to memory of 1924	1276	file.exe	30
PID 1276 wrote to memory of 1924	1276	file.exe	30
PID 1276 wrote to memory of 596	1276	file.exe	32
PID 1276 wrote to memory of 596	1276	file.exe	32
PID 1276 wrote to memory of 596	1276	file.exe	32
PID 1276 wrote to memory of 596	1276	file.exe	32
PID 1276 wrote to memory of 2020	1276	file.exe	34
PID 1276 wrote to memory of 2020	1276	file.exe	34
PID 1276 wrote to memory of 2020	1276	file.exe	34
PID 1276 wrote to memory of 2020	1276	file.exe	34
PID 1276 wrote to memory of 1444	1276	file.exe	36
PID 1276 wrote to memory of 1444	1276	file.exe	36
PID 1276 wrote to memory of 1444	1276	file.exe	36
PID 1276 wrote to memory of 1444	1276	file.exe	36
PID 1276 wrote to memory of 1616	1276	file.exe	39
PID 1276 wrote to memory of 1616	1276	file.exe	39
PID 1276 wrote to memory of 1616	1276	file.exe	39
PID 1276 wrote to memory of 1616	1276	file.exe	39
PID 1500 wrote to memory of 1804	1500	gwylcuf.exe	41
PID 1500 wrote to memory of 1804	1500	gwylcuf.exe	41
PID 1500 wrote to memory of 1804	1500	gwylcuf.exe	41
PID 1500 wrote to memory of 1804	1500	gwylcuf.exe	41
PID 1500 wrote to memory of 1804	1500	gwylcuf.exe	41
PID 1500 wrote to memory of 1804	1500	gwylcuf.exe	41

C:\Users\Admin\AppData\Local\Temp\file.exe
"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:1276
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\yrgridiu\
  2⤵
  PID:472
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\gwylcuf.exe" C:\Windows\SysWOW64\yrgridiu\
  2⤵
  PID:1924
- C:\Windows\SysWOW64\sc.exe
  "C:\Windows\System32\sc.exe" create yrgridiu binPath= "C:\Windows\SysWOW64\yrgridiu\gwylcuf.exe /d\"C:\Users\Admin\AppData\Local\Temp\file.exe\"" type= own start= auto DisplayName= "wifi support"
  2⤵
  - Launches sc.exe
  PID:596
- C:\Windows\SysWOW64\sc.exe
  "C:\Windows\System32\sc.exe" description yrgridiu "wifi internet conection"
  2⤵
  - Launches sc.exe
  PID:2020
- C:\Windows\SysWOW64\sc.exe
  "C:\Windows\System32\sc.exe" start yrgridiu
  2⤵
  - Launches sc.exe
  PID:1444
- C:\Windows\SysWOW64\netsh.exe
  "C:\Windows\System32\netsh.exe" advfirewall firewall add rule name="Host-process for services of Windows" dir=in action=allow program="C:\Windows\SysWOW64\svchost.exe" enable=yes>nul
  2⤵
  - Modifies Windows Firewall
  PID:1616

C:\Windows\SysWOW64\yrgridiu\gwylcuf.exe
C:\Windows\SysWOW64\yrgridiu\gwylcuf.exe /d"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Executes dropped EXE
- Suspicious use of SetThreadContext
- Suspicious use of WriteProcessMemory
PID:1500
- C:\Windows\SysWOW64\svchost.exe
  svchost.exe
  2⤵
  - Windows security bypass
  - Sets service image path in registry
  - Deletes itself
  - Drops file in System32 directory
  - Modifies data under HKEY_USERS
  PID:1804

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Modify Existing Service

T1031

New Service

T1050

Registry Run Keys / Startup Folder

T1060

Privilege Escalation

New Service

T1050

Defense Evasion

Disabling Security Tools

T1089

Modify Registry

T1112

Credential Access

Discovery

System Information Discovery

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Local\Temp\gwylcuf.exe

Filesize
13.9MB

MD5
8ec5b3299303076d6ae2e5cc02cdf273

SHA1
bed25e11f971797a8970662539e2d60445775ad9

SHA256
42d9fbc50cb1f3234705f759a4b456827b357c7f5e0100ce926a4f7f54afca71

SHA512
b1b5a44cdd314572ed838c468cb3b17dea976fcc25300e6293939f664f132f94381d11d086a9517b027e4b564c692cb30e3a2b4ad57ae05cf4216694eb63bf52

Download Submit
C:\Windows\SysWOW64\yrgridiu\gwylcuf.exe

Filesize
13.9MB

MD5
8ec5b3299303076d6ae2e5cc02cdf273

SHA1
bed25e11f971797a8970662539e2d60445775ad9

SHA256
42d9fbc50cb1f3234705f759a4b456827b357c7f5e0100ce926a4f7f54afca71

SHA512
b1b5a44cdd314572ed838c468cb3b17dea976fcc25300e6293939f664f132f94381d11d086a9517b027e4b564c692cb30e3a2b4ad57ae05cf4216694eb63bf52

Download Submit
memory/1276-57-0x0000000000400000-0x00000000004C7000-memory.dmp

Filesize
796KB

Download
memory/1276-54-0x0000000076381000-0x0000000076383000-memory.dmp

Filesize
8KB

Download
memory/1276-56-0x0000000000220000-0x0000000000233000-memory.dmp

Filesize
76KB

Download
memory/1276-55-0x00000000005AC000-0x00000000005C1000-memory.dmp

Filesize
84KB

Download
memory/1276-66-0x00000000005AC000-0x00000000005C1000-memory.dmp

Filesize
84KB

Download
memory/1276-67-0x0000000000400000-0x00000000004C7000-memory.dmp

Filesize
796KB

Download
memory/1500-77-0x0000000000400000-0x00000000004C7000-memory.dmp

Filesize
796KB

Download
memory/1500-74-0x000000000058C000-0x00000000005A1000-memory.dmp

Filesize
84KB

Download
memory/1804-72-0x00000000000C0000-0x00000000000D5000-memory.dmp

Filesize
84KB

Download
memory/1804-70-0x00000000000C0000-0x00000000000D5000-memory.dmp

Filesize
84KB

Download
memory/1804-79-0x00000000000C0000-0x00000000000D5000-memory.dmp

Filesize
84KB

Download
memory/1804-80-0x00000000000C0000-0x00000000000D5000-memory.dmp

Filesize
84KB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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