tofsee | 54f74659a4f85bab878e448b3ae96242c24f98f054cd7a16ce2a6b6daae4a70e

General

Target

file.exe
Size

233KB
MD5

b76e2d8db8266762c770fbf801b33917
SHA1

f8a8d5ced370552210f2b449ec2822c48e470bac
SHA256

54f74659a4f85bab878e448b3ae96242c24f98f054cd7a16ce2a6b6daae4a70e
SHA512

55b1de5e83d1f2cb7840b2eee2ac40dfcb0c1d289568b63a41e4b459f5fbb599c934df2805c1dd9b2b344133a39d4c2950997796605624ffff4dac1b32d7f76b
SSDEEP

3072:EpqwYirEGOie1jXG7NlKAwQgbzRKr+6g3SVdwMByxMKiY54mYidF5Fkn:fwkGOCKbQIKL8vChm4m

Score

10^/10

tofsee evasion persistence trojan

Malware Config

Extracted

Family

tofsee

C2

vanaheim.cn

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

Processes:

svchost.exe

description	ioc	process
Set value (int)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows Defender\Exclusions\Paths\C:\Windows\SysWOW64\nvhasyfg = "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

Processes:

netsh.exe

pid process

1940 netsh.exe

pid	process
1940	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\nvhasyfg\ImagePath = "C:\\Windows\\SysWOW64\\nvhasyfg\\lsremmuy.exe"	svchost.exe

Deletes itself 1 IoCs

Processes:

svchost.exe

pid process

1088 svchost.exe
Executes dropped EXE 1 IoCs

Processes:

lsremmuy.exe

pid process

1816 lsremmuy.exe
Drops file in System32 directory 1 IoCs

Processes:

svchost.exe

description ioc process

File created C:\Windows\SysWOW64\config\systemprofile:.repos svchost.exe
Suspicious use of SetThreadContext 1 IoCs

Processes:

lsremmuy.exe

description pid process target process

PID 1816 set thread context of 1088 1816 lsremmuy.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

432 sc.exe
576 sc.exe
1160 sc.exe
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).

System Information Discovery
T1082

pid	process
1088	svchost.exe

pid	process
1816	lsremmuy.exe

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

description	pid	process	target process
PID 1816 set thread context of 1088	1816	lsremmuy.exe	svchost.exe

pid	process
432	sc.exe
576	sc.exe
1160	sc.exe

Modifies data under HKEY_USERS 2 IoCs

Processes:

svchost.exe

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

Processes:

file.exelsremmuy.exe

description	pid	process	target process
PID 928 wrote to memory of 1492	928	file.exe	cmd.exe
PID 928 wrote to memory of 1492	928	file.exe	cmd.exe
PID 928 wrote to memory of 1492	928	file.exe	cmd.exe
PID 928 wrote to memory of 1492	928	file.exe	cmd.exe
PID 928 wrote to memory of 1500	928	file.exe	cmd.exe
PID 928 wrote to memory of 1500	928	file.exe	cmd.exe
PID 928 wrote to memory of 1500	928	file.exe	cmd.exe
PID 928 wrote to memory of 1500	928	file.exe	cmd.exe
PID 928 wrote to memory of 432	928	file.exe	sc.exe
PID 928 wrote to memory of 432	928	file.exe	sc.exe
PID 928 wrote to memory of 432	928	file.exe	sc.exe
PID 928 wrote to memory of 432	928	file.exe	sc.exe
PID 928 wrote to memory of 576	928	file.exe	sc.exe
PID 928 wrote to memory of 576	928	file.exe	sc.exe
PID 928 wrote to memory of 576	928	file.exe	sc.exe
PID 928 wrote to memory of 576	928	file.exe	sc.exe
PID 928 wrote to memory of 1160	928	file.exe	sc.exe
PID 928 wrote to memory of 1160	928	file.exe	sc.exe
PID 928 wrote to memory of 1160	928	file.exe	sc.exe
PID 928 wrote to memory of 1160	928	file.exe	sc.exe
PID 1816 wrote to memory of 1088	1816	lsremmuy.exe	svchost.exe
PID 1816 wrote to memory of 1088	1816	lsremmuy.exe	svchost.exe
PID 1816 wrote to memory of 1088	1816	lsremmuy.exe	svchost.exe
PID 1816 wrote to memory of 1088	1816	lsremmuy.exe	svchost.exe
PID 1816 wrote to memory of 1088	1816	lsremmuy.exe	svchost.exe
PID 1816 wrote to memory of 1088	1816	lsremmuy.exe	svchost.exe
PID 928 wrote to memory of 1940	928	file.exe	netsh.exe
PID 928 wrote to memory of 1940	928	file.exe	netsh.exe
PID 928 wrote to memory of 1940	928	file.exe	netsh.exe
PID 928 wrote to memory of 1940	928	file.exe	netsh.exe

C:\Users\Admin\AppData\Local\Temp\file.exe
"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:928
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\nvhasyfg\
  2⤵
  PID:1492
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\lsremmuy.exe" C:\Windows\SysWOW64\nvhasyfg\
  2⤵
  PID:1500
- C:\Windows\SysWOW64\sc.exe
  "C:\Windows\System32\sc.exe" create nvhasyfg binPath= "C:\Windows\SysWOW64\nvhasyfg\lsremmuy.exe /d\"C:\Users\Admin\AppData\Local\Temp\file.exe\"" type= own start= auto DisplayName= "wifi support"
  2⤵
  - Launches sc.exe
  PID:432
- C:\Windows\SysWOW64\sc.exe
  "C:\Windows\System32\sc.exe" description nvhasyfg "wifi internet conection"
  2⤵
  - Launches sc.exe
  PID:576
- C:\Windows\SysWOW64\sc.exe
  "C:\Windows\System32\sc.exe" start nvhasyfg
  2⤵
  - Launches sc.exe
  PID:1160
- 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:1940

C:\Windows\SysWOW64\nvhasyfg\lsremmuy.exe
C:\Windows\SysWOW64\nvhasyfg\lsremmuy.exe /d"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Executes dropped EXE
- Suspicious use of SetThreadContext
- Suspicious use of WriteProcessMemory
PID:1816
- 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:1088

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Modify Existing Service

New Service

Registry Run Keys / Startup Folder

1

T1060

Privilege Escalation

New Service

1

T1050

Defense Evasion

Disabling Security Tools

Modify Registry

Credential Access

Discovery

System Information Discovery

1

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

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

Filesize
14.2MB

MD5
960687d03113fa6eea7cd17b0fd936e9

SHA1
f3c6f978f2b100d4548e90461881c870dc84c3cc

SHA256
4e8a67e55b096c1da25c370bdda20fe4090cc41d81e573843c1ab55b274bb046

SHA512
c484d60ad7fa072cf4c78e993678258ee36bba3a3ea9893ae0886edb709d8fbee172f5a8fa0bc944940475d8821f98d1b2981731e6f85593a0603d08389ccbbc

Download Submit
C:\Windows\SysWOW64\nvhasyfg\lsremmuy.exe

Filesize
14.2MB

MD5
960687d03113fa6eea7cd17b0fd936e9

SHA1
f3c6f978f2b100d4548e90461881c870dc84c3cc

SHA256
4e8a67e55b096c1da25c370bdda20fe4090cc41d81e573843c1ab55b274bb046

SHA512
c484d60ad7fa072cf4c78e993678258ee36bba3a3ea9893ae0886edb709d8fbee172f5a8fa0bc944940475d8821f98d1b2981731e6f85593a0603d08389ccbbc

Download Submit
memory/928-56-0x0000000000220000-0x0000000000233000-memory.dmp

Filesize
76KB

Download
memory/928-65-0x0000000000400000-0x00000000006B8000-memory.dmp

Filesize
2.7MB

Download
memory/1088-62-0x00000000000D0000-0x00000000000E5000-memory.dmp

Filesize
84KB

Download
memory/1088-61-0x000000007EFDE000-0x000000007EFDF000-memory.dmp

Filesize
4KB

Download
memory/1088-60-0x00000000000D0000-0x00000000000E5000-memory.dmp

Filesize
84KB

Download
memory/1088-67-0x00000000000D0000-0x00000000000E5000-memory.dmp

Filesize
84KB

Download
memory/1088-68-0x00000000000D0000-0x00000000000E5000-memory.dmp

Filesize
84KB

Download
memory/1088-69-0x00000000000D0000-0x00000000000E5000-memory.dmp

Filesize
84KB

Download
memory/1088-70-0x00000000000D0000-0x00000000000E5000-memory.dmp

Filesize
84KB

Download
memory/1816-66-0x0000000000400000-0x00000000006B8000-memory.dmp

Filesize
2.7MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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