tofsee | a71e5f2db834e7eb59cb1089a56dbd3e0b3dfcfc605efb9a8a42b17d3f19445c

General

Target

file.exe
Size

347KB
MD5

0c1708ed3939df691fcc921eeca929e8
SHA1

1423af702026959fb660354fdab5252f7342b763
SHA256

a71e5f2db834e7eb59cb1089a56dbd3e0b3dfcfc605efb9a8a42b17d3f19445c
SHA512

502ee675cb930d2f12e7c7f012296831fcefef2c27983dcc9f15d0f41616cbf9857f5bc63d22849d419ac7d4ca80cc6aa9809c1ba4c6343a4b45ddc935e0784c
SSDEEP

6144:ieI4cg3BjROHIH8SOm28gIk1nvPCX6tbe4:iercM3OHIH8zmwIk1vPQ6tq4

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\tkzlcirn = "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

1584 netsh.exe

pid	process
1584	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\tkzlcirn\ImagePath = "C:\\Windows\\SysWOW64\\tkzlcirn\\foufdsk.exe"	svchost.exe

Deletes itself 1 IoCs

Processes:

svchost.exe

pid process

912 svchost.exe
Executes dropped EXE 1 IoCs

Processes:

foufdsk.exe

pid process

1724 foufdsk.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:

foufdsk.exe

description pid process target process

PID 1724 set thread context of 912 1724 foufdsk.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

1412 sc.exe
1452 sc.exe
432 sc.exe
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

System Information Discovery
T1082

pid	process
912	svchost.exe

pid	process
1724	foufdsk.exe

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

description	pid	process	target process
PID 1724 set thread context of 912	1724	foufdsk.exe	svchost.exe

pid	process
1412	sc.exe
1452	sc.exe
432	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.exefoufdsk.exe

description	pid	process	target process
PID 2012 wrote to memory of 1996	2012	file.exe	cmd.exe
PID 2012 wrote to memory of 1996	2012	file.exe	cmd.exe
PID 2012 wrote to memory of 1996	2012	file.exe	cmd.exe
PID 2012 wrote to memory of 1996	2012	file.exe	cmd.exe
PID 2012 wrote to memory of 1948	2012	file.exe	cmd.exe
PID 2012 wrote to memory of 1948	2012	file.exe	cmd.exe
PID 2012 wrote to memory of 1948	2012	file.exe	cmd.exe
PID 2012 wrote to memory of 1948	2012	file.exe	cmd.exe
PID 2012 wrote to memory of 432	2012	file.exe	sc.exe
PID 2012 wrote to memory of 432	2012	file.exe	sc.exe
PID 2012 wrote to memory of 432	2012	file.exe	sc.exe
PID 2012 wrote to memory of 432	2012	file.exe	sc.exe
PID 2012 wrote to memory of 1412	2012	file.exe	sc.exe
PID 2012 wrote to memory of 1412	2012	file.exe	sc.exe
PID 2012 wrote to memory of 1412	2012	file.exe	sc.exe
PID 2012 wrote to memory of 1412	2012	file.exe	sc.exe
PID 2012 wrote to memory of 1452	2012	file.exe	sc.exe
PID 2012 wrote to memory of 1452	2012	file.exe	sc.exe
PID 2012 wrote to memory of 1452	2012	file.exe	sc.exe
PID 2012 wrote to memory of 1452	2012	file.exe	sc.exe
PID 1724 wrote to memory of 912	1724	foufdsk.exe	svchost.exe
PID 1724 wrote to memory of 912	1724	foufdsk.exe	svchost.exe
PID 1724 wrote to memory of 912	1724	foufdsk.exe	svchost.exe
PID 1724 wrote to memory of 912	1724	foufdsk.exe	svchost.exe
PID 1724 wrote to memory of 912	1724	foufdsk.exe	svchost.exe
PID 1724 wrote to memory of 912	1724	foufdsk.exe	svchost.exe
PID 2012 wrote to memory of 1584	2012	file.exe	netsh.exe
PID 2012 wrote to memory of 1584	2012	file.exe	netsh.exe
PID 2012 wrote to memory of 1584	2012	file.exe	netsh.exe
PID 2012 wrote to memory of 1584	2012	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:2012
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\tkzlcirn\
  2⤵
  PID:1996
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\foufdsk.exe" C:\Windows\SysWOW64\tkzlcirn\
  2⤵
  PID:1948
- C:\Windows\SysWOW64\sc.exe
  "C:\Windows\System32\sc.exe" create tkzlcirn binPath= "C:\Windows\SysWOW64\tkzlcirn\foufdsk.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 tkzlcirn "wifi internet conection"
  2⤵
  - Launches sc.exe
  PID:1412
- C:\Windows\SysWOW64\sc.exe
  "C:\Windows\System32\sc.exe" start tkzlcirn
  2⤵
  - Launches sc.exe
  PID:1452
- 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:1584

C:\Windows\SysWOW64\tkzlcirn\foufdsk.exe
C:\Windows\SysWOW64\tkzlcirn\foufdsk.exe /d"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Executes dropped EXE
- Suspicious use of SetThreadContext
- Suspicious use of WriteProcessMemory
PID:1724
- 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:912

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\foufdsk.exe

Filesize
14.7MB

MD5
cf9b2531117ca12898505fbc58757ba9

SHA1
fac7d0b6d4c246831bebc552bcf73f70d62644cb

SHA256
4de58db758aab148a35609882523b7361f6fd2fc997e000106e38c0554ef0f2c

SHA512
57e77d851804536c7702d084aafaa0be07faf9e0d9cb60cf20e4e25b064815f60e47ba0031ebbcb1627956630bf5497130d793e8c4f9f55c372482f717632138

Download Submit
C:\Windows\SysWOW64\tkzlcirn\foufdsk.exe

Filesize
14.7MB

MD5
cf9b2531117ca12898505fbc58757ba9

SHA1
fac7d0b6d4c246831bebc552bcf73f70d62644cb

SHA256
4de58db758aab148a35609882523b7361f6fd2fc997e000106e38c0554ef0f2c

SHA512
57e77d851804536c7702d084aafaa0be07faf9e0d9cb60cf20e4e25b064815f60e47ba0031ebbcb1627956630bf5497130d793e8c4f9f55c372482f717632138

Download Submit
memory/912-61-0x000000007EFDE000-0x000000007EFDF000-memory.dmp

Filesize
4KB

Download
memory/912-60-0x0000000000080000-0x0000000000095000-memory.dmp

Filesize
84KB

Download
memory/912-62-0x0000000000080000-0x0000000000095000-memory.dmp

Filesize
84KB

Download
memory/912-67-0x0000000000080000-0x0000000000095000-memory.dmp

Filesize
84KB

Download
memory/912-68-0x0000000000080000-0x0000000000095000-memory.dmp

Filesize
84KB

Download
memory/912-69-0x0000000000080000-0x0000000000095000-memory.dmp

Filesize
84KB

Download
memory/912-71-0x0000000000080000-0x0000000000095000-memory.dmp

Filesize
84KB

Download
memory/1724-63-0x0000000000400000-0x00000000007FC000-memory.dmp

Filesize
4.0MB

Download
memory/2012-56-0x0000000000230000-0x0000000000243000-memory.dmp

Filesize
76KB

Download
memory/2012-66-0x0000000000400000-0x00000000007FC000-memory.dmp

Filesize
4.0MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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Downloads