tofsee | af4515bb1ca19b5fdc2cf47391594cb4ca3f2c3063a1c703e4331e741d31e4fc

General

Target

file.exe
Size

167KB
MD5

65e43f6b5f4bbf71f6ecab7473d5f169
SHA1

647be05e012efc56178c827e429208f773e7358c
SHA256

af4515bb1ca19b5fdc2cf47391594cb4ca3f2c3063a1c703e4331e741d31e4fc
SHA512

9da8f0b9be029a65d2971ccb936a0c0a08a33275f3260ac232f497744ba8bb088dd377a0aaf2c083cdc3d2bb0d1f39d9af19ac79f245276ce64c43fe1adb07c9
SSDEEP

3072:RPJ1pyY1u2XpS5VL7++e3BuFF9uOnWR0vkqNuG2:N0iZXh+eKFlWmk+u

Score

10^/10

tofsee evasion persistence trojan

Malware Config

Extracted

Family

tofsee

C2

svartalfheim.top

jotunheim.name

Signatures

Tofsee
Backdoor/botnet which carries out malicious activities based on commands from a C2 server.
trojan tofsee
Creates new service(s) 1 TTPs
persistence

New Service
T1050
Executes dropped EXE 1 IoCs

Processes:

zspxohby.exe

pid process

100 zspxohby.exe
Modifies Windows Firewall 1 TTPs 1 IoCs
evasion

Modify Existing Service
T1031

Processes:

netsh.exe

pid process

3996 netsh.exe

pid	process
100	zspxohby.exe

pid	process
3996	netsh.exe

Sets service image path in registry 2 TTPs 1 IoCs

persistence

Registry Run Keys / Startup Folder

T1060

Modify Registry

T1112

Processes:

svchost.exe

description	ioc	process
Set value (str)	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Services\asccjwnv\ImagePath = "C:\\Windows\\SysWOW64\\asccjwnv\\zspxohby.exe"	svchost.exe

Checks computer location settings 2 TTPs 1 IoCs
Looks up country code configured in the registry, likely geofence.

Query Registry
T1012

System Information Discovery
T1082

Processes:

file.exe

description ioc process

Key value queried \REGISTRY\USER\S-1-5-21-929662420-1054238289-2961194603-1000\Control Panel\International\Geo\Nation file.exe
Suspicious use of SetThreadContext 1 IoCs

Processes:

zspxohby.exe

description pid process target process

PID 100 set thread context of 4628 100 zspxohby.exe svchost.exe
Launches sc.exe 3 IoCs
Sc.exe is a Windows utlilty to control services on the system.

Processes:

sc.exesc.exesc.exe

pid process

2400 sc.exe
3480 sc.exe
1848 sc.exe
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

System Information Discovery
T1082
Program crash 2 IoCs

Processes:

WerFault.exeWerFault.exe

pid pid_target process target process

3432 4348 WerFault.exe file.exe
4656 100 WerFault.exe zspxohby.exe

description	ioc	process
Key value queried	\REGISTRY\USER\S-1-5-21-929662420-1054238289-2961194603-1000\Control Panel\International\Geo\Nation	file.exe

description	pid	process	target process
PID 100 set thread context of 4628	100	zspxohby.exe	svchost.exe

pid	process
2400	sc.exe
3480	sc.exe
1848	sc.exe

pid	pid_target	process	target process
3432	4348	WerFault.exe	file.exe
4656	100	WerFault.exe	zspxohby.exe

Suspicious use of WriteProcessMemory 23 IoCs

Processes:

file.exezspxohby.exe

description	pid	process	target process
PID 4348 wrote to memory of 4124	4348	file.exe	cmd.exe
PID 4348 wrote to memory of 4124	4348	file.exe	cmd.exe
PID 4348 wrote to memory of 4124	4348	file.exe	cmd.exe
PID 4348 wrote to memory of 552	4348	file.exe	cmd.exe
PID 4348 wrote to memory of 552	4348	file.exe	cmd.exe
PID 4348 wrote to memory of 552	4348	file.exe	cmd.exe
PID 4348 wrote to memory of 2400	4348	file.exe	sc.exe
PID 4348 wrote to memory of 2400	4348	file.exe	sc.exe
PID 4348 wrote to memory of 2400	4348	file.exe	sc.exe
PID 4348 wrote to memory of 3480	4348	file.exe	sc.exe
PID 4348 wrote to memory of 3480	4348	file.exe	sc.exe
PID 4348 wrote to memory of 3480	4348	file.exe	sc.exe
PID 4348 wrote to memory of 1848	4348	file.exe	sc.exe
PID 4348 wrote to memory of 1848	4348	file.exe	sc.exe
PID 4348 wrote to memory of 1848	4348	file.exe	sc.exe
PID 4348 wrote to memory of 3996	4348	file.exe	netsh.exe
PID 4348 wrote to memory of 3996	4348	file.exe	netsh.exe
PID 4348 wrote to memory of 3996	4348	file.exe	netsh.exe
PID 100 wrote to memory of 4628	100	zspxohby.exe	svchost.exe
PID 100 wrote to memory of 4628	100	zspxohby.exe	svchost.exe
PID 100 wrote to memory of 4628	100	zspxohby.exe	svchost.exe
PID 100 wrote to memory of 4628	100	zspxohby.exe	svchost.exe
PID 100 wrote to memory of 4628	100	zspxohby.exe	svchost.exe

C:\Users\Admin\AppData\Local\Temp\file.exe
"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Checks computer location settings
- Suspicious use of WriteProcessMemory
PID:4348

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\asccjwnv\
2⤵
PID:4124

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\zspxohby.exe" C:\Windows\SysWOW64\asccjwnv\
2⤵
PID:552

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" create asccjwnv binPath= "C:\Windows\SysWOW64\asccjwnv\zspxohby.exe /d\"C:\Users\Admin\AppData\Local\Temp\file.exe\"" type= own start= auto DisplayName= "wifi support"
2⤵
- Launches sc.exe
PID:2400

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" description asccjwnv "wifi internet conection"
2⤵
- Launches sc.exe
PID:3480

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" start asccjwnv
2⤵
- Launches sc.exe
PID:1848

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:3996

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -u -p 4348 -s 1036
2⤵
- Program crash
PID:3432

C:\Windows\SysWOW64\asccjwnv\zspxohby.exe
C:\Windows\SysWOW64\asccjwnv\zspxohby.exe /d"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Executes dropped EXE
- Suspicious use of SetThreadContext
- Suspicious use of WriteProcessMemory
PID:100

C:\Windows\SysWOW64\svchost.exe
svchost.exe
2⤵
- Sets service image path in registry
PID:4628

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -u -p 100 -s 512
2⤵
- Program crash
PID:4656

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 464 -p 4348 -ip 4348
1⤵
PID:4824

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 532 -p 100 -ip 100
1⤵
PID:3632

Network

MITRE ATT&CK Matrix ATT&CK v6

Initial Access

Execution

Persistence

New Service

1

T1050

Modify Existing Service

1

T1031

Registry Run Keys / Startup Folder

1

T1060

Privilege Escalation

New Service

1

T1050

Defense Evasion

Modify Registry

1

T1112

Credential Access

Discovery

Query Registry

1

T1012

System Information Discovery

2

T1082

Lateral Movement

Collection

Exfiltration

Command and Control

Impact

Replay Monitor

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Downloads

C:\Users\Admin\AppData\Local\Temp\zspxohby.exe
Filesize
10.4MB

MD5
b4c79517798df4bfcc5a8fbce68bfbd8

SHA1
1ccac7670dc9535c50be99215e8850953cd5807f

SHA256
432e8892a83e59474fa0a745660f1b56a5a20ad5dfe9d5611619a1d6169f5621

SHA512
621db3e2a170e12f20f0678a677b15454006207d041e6bdfaa2cdf242e6c6ba36ac2ce828a36892bc97f9ee4edb976eb962cf0f54bb1d9b73b1859b43ed13ba9

Download Submit
C:\Windows\SysWOW64\asccjwnv\zspxohby.exe
Filesize
10.4MB

MD5
b4c79517798df4bfcc5a8fbce68bfbd8

SHA1
1ccac7670dc9535c50be99215e8850953cd5807f

SHA256
432e8892a83e59474fa0a745660f1b56a5a20ad5dfe9d5611619a1d6169f5621

SHA512
621db3e2a170e12f20f0678a677b15454006207d041e6bdfaa2cdf242e6c6ba36ac2ce828a36892bc97f9ee4edb976eb962cf0f54bb1d9b73b1859b43ed13ba9

Download Submit
memory/100-149-0x0000000000400000-0x000000000070B000-memory.dmp

Filesize
3.0MB

Download
memory/100-148-0x00000000007A9000-0x00000000007B9000-memory.dmp

Filesize
64KB

Download
memory/552-136-0x0000000000000000-mapping.dmp

Download
memory/1848-140-0x0000000000000000-mapping.dmp

Download
memory/2400-138-0x0000000000000000-mapping.dmp

Download
memory/3480-139-0x0000000000000000-mapping.dmp

Download
memory/3996-142-0x0000000000000000-mapping.dmp

Download
memory/4124-135-0x0000000000000000-mapping.dmp

Download
memory/4348-133-0x0000000000890000-0x00000000008A3000-memory.dmp

Filesize
76KB

Download
memory/4348-143-0x0000000000400000-0x000000000070B000-memory.dmp

Filesize
3.0MB

Download
memory/4348-134-0x0000000000400000-0x000000000070B000-memory.dmp

Filesize
3.0MB

Download
memory/4348-132-0x000000000098D000-0x000000000099D000-memory.dmp

Filesize
64KB

Download
memory/4628-144-0x0000000000000000-mapping.dmp

Download
memory/4628-145-0x0000000000EB0000-0x0000000000EC5000-memory.dmp

Filesize
84KB

Download
memory/4628-150-0x0000000000EB0000-0x0000000000EC5000-memory.dmp

Filesize
84KB

Download
memory/4628-151-0x0000000000EB0000-0x0000000000EC5000-memory.dmp

Filesize
84KB

Download

Analysis

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