tofsee | ae103a988f889f4120a5d21bdf08d4ff41588c26c4efab1c604cab29dc5632a2

General

Target

file.exe
Size

178KB
MD5

faca2fb4b7df8b02263be3f101775d8d
SHA1

1ee11a0311a1507b66d76b668eaa1806794692a7
SHA256

ae103a988f889f4120a5d21bdf08d4ff41588c26c4efab1c604cab29dc5632a2
SHA512

3f8dd1204b45afb76df8137f1a46a40a6b53c3bf98b80959724d27bc1da1e1e48fb28c18ebbb4940b30ac6b98e1b04f4ccb937e7a9b836802bfbea903a88ff7c
SSDEEP

3072:knSQXMYrEDcw6d5QWBhf7RBkDuaad402UlVDYJ5V2RBB2Wk2:mDEDcwdYJRBSuld40vYJ5yB

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

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\affequrw = "0"	svchost.exe

Creates new service(s) 1 TTPs
persistence

New Service
T1050
Executes dropped EXE 1 IoCs

Processes:

rxkfyfsn.exe

pid process

1424 rxkfyfsn.exe
Modifies Windows Firewall 1 TTPs 1 IoCs
evasion

Modify Existing Service
T1031

Processes:

netsh.exe

pid process

1532 netsh.exe

pid	process
1424	rxkfyfsn.exe

pid	process
1532	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\affequrw\ImagePath = "C:\\Windows\\SysWOW64\\affequrw\\rxkfyfsn.exe"	svchost.exe

Deletes itself 1 IoCs

Processes:

svchost.exe

pid process

1536 svchost.exe
Suspicious use of SetThreadContext 1 IoCs

Processes:

rxkfyfsn.exe

description pid process target process

PID 1424 set thread context of 1536 1424 rxkfyfsn.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

564 sc.exe
1988 sc.exe
820 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
1536	svchost.exe

description	pid	process	target process
PID 1424 set thread context of 1536	1424	rxkfyfsn.exe	svchost.exe

pid	process
564	sc.exe
1988	sc.exe
820	sc.exe

Suspicious use of WriteProcessMemory 30 IoCs

Processes:

file.exerxkfyfsn.exe

description	pid	process	target process
PID 1052 wrote to memory of 1092	1052	file.exe	cmd.exe
PID 1052 wrote to memory of 1092	1052	file.exe	cmd.exe
PID 1052 wrote to memory of 1092	1052	file.exe	cmd.exe
PID 1052 wrote to memory of 1092	1052	file.exe	cmd.exe
PID 1052 wrote to memory of 1148	1052	file.exe	cmd.exe
PID 1052 wrote to memory of 1148	1052	file.exe	cmd.exe
PID 1052 wrote to memory of 1148	1052	file.exe	cmd.exe
PID 1052 wrote to memory of 1148	1052	file.exe	cmd.exe
PID 1052 wrote to memory of 564	1052	file.exe	sc.exe
PID 1052 wrote to memory of 564	1052	file.exe	sc.exe
PID 1052 wrote to memory of 564	1052	file.exe	sc.exe
PID 1052 wrote to memory of 564	1052	file.exe	sc.exe
PID 1052 wrote to memory of 1988	1052	file.exe	sc.exe
PID 1052 wrote to memory of 1988	1052	file.exe	sc.exe
PID 1052 wrote to memory of 1988	1052	file.exe	sc.exe
PID 1052 wrote to memory of 1988	1052	file.exe	sc.exe
PID 1052 wrote to memory of 820	1052	file.exe	sc.exe
PID 1052 wrote to memory of 820	1052	file.exe	sc.exe
PID 1052 wrote to memory of 820	1052	file.exe	sc.exe
PID 1052 wrote to memory of 820	1052	file.exe	sc.exe
PID 1052 wrote to memory of 1532	1052	file.exe	netsh.exe
PID 1052 wrote to memory of 1532	1052	file.exe	netsh.exe
PID 1052 wrote to memory of 1532	1052	file.exe	netsh.exe
PID 1052 wrote to memory of 1532	1052	file.exe	netsh.exe
PID 1424 wrote to memory of 1536	1424	rxkfyfsn.exe	svchost.exe
PID 1424 wrote to memory of 1536	1424	rxkfyfsn.exe	svchost.exe
PID 1424 wrote to memory of 1536	1424	rxkfyfsn.exe	svchost.exe
PID 1424 wrote to memory of 1536	1424	rxkfyfsn.exe	svchost.exe
PID 1424 wrote to memory of 1536	1424	rxkfyfsn.exe	svchost.exe
PID 1424 wrote to memory of 1536	1424	rxkfyfsn.exe	svchost.exe

C:\Users\Admin\AppData\Local\Temp\file.exe
"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:1052

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\affequrw\
2⤵
PID:1092

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\rxkfyfsn.exe" C:\Windows\SysWOW64\affequrw\
2⤵
PID:1148

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" create affequrw binPath= "C:\Windows\SysWOW64\affequrw\rxkfyfsn.exe /d\"C:\Users\Admin\AppData\Local\Temp\file.exe\"" type= own start= auto DisplayName= "wifi support"
2⤵
- Launches sc.exe
PID:564

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" description affequrw "wifi internet conection"
2⤵
- Launches sc.exe
PID:1988

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" start affequrw
2⤵
- Launches sc.exe
PID:820

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:1532

C:\Windows\SysWOW64\affequrw\rxkfyfsn.exe
C:\Windows\SysWOW64\affequrw\rxkfyfsn.exe /d"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Executes dropped EXE
- Suspicious use of SetThreadContext
- Suspicious use of WriteProcessMemory
PID:1424

C:\Windows\SysWOW64\svchost.exe
svchost.exe
2⤵
- Windows security bypass
- Sets service image path in registry
- Deletes itself
PID:1536

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

Disabling Security Tools

1

T1089

Modify Registry

2

T1112

Credential Access

Discovery

System Information Discovery

1

T1082

Lateral Movement

Collection

Exfiltration

Command and Control

Impact

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Downloads

C:\Users\Admin\AppData\Local\Temp\rxkfyfsn.exe
Filesize
13.4MB

MD5
e4a0586959da1597a7a2aa2aa2107f0d

SHA1
4e2e03693f9d0e09422c92334f69f51afd1e6b36

SHA256
b8b84cfbd80e9643236125844acfb5d7670836bbad4b1abf07c4561b994a29f4

SHA512
ef303ea1af5ecc11fe58975c6ea539681f21c7dc532f3c110f483dbb396b6361e5a65d2d58067aa3c12090bf1f104afaba183b680cbe2c29ea581c9f15941dab

Download Submit
C:\Windows\SysWOW64\affequrw\rxkfyfsn.exe
Filesize
13.4MB

MD5
e4a0586959da1597a7a2aa2aa2107f0d

SHA1
4e2e03693f9d0e09422c92334f69f51afd1e6b36

SHA256
b8b84cfbd80e9643236125844acfb5d7670836bbad4b1abf07c4561b994a29f4

SHA512
ef303ea1af5ecc11fe58975c6ea539681f21c7dc532f3c110f483dbb396b6361e5a65d2d58067aa3c12090bf1f104afaba183b680cbe2c29ea581c9f15941dab

Download Submit
memory/564-61-0x0000000000000000-mapping.dmp

Download
memory/820-63-0x0000000000000000-mapping.dmp

Download
memory/1052-66-0x00000000002EB000-0x00000000002FC000-memory.dmp

Filesize
68KB

Download
memory/1052-55-0x00000000002EB000-0x00000000002FC000-memory.dmp

Filesize
68KB

Download
memory/1052-56-0x00000000001B0000-0x00000000001C3000-memory.dmp

Filesize
76KB

Download
memory/1052-57-0x0000000000400000-0x000000000070E000-memory.dmp

Filesize
3.1MB

Download
memory/1052-54-0x0000000075291000-0x0000000075293000-memory.dmp

Filesize
8KB

Download
memory/1052-64-0x00000000002EB000-0x00000000002FC000-memory.dmp

Filesize
68KB

Download
memory/1052-67-0x0000000000400000-0x000000000070E000-memory.dmp

Filesize
3.1MB

Download
memory/1092-58-0x0000000000000000-mapping.dmp

Download
memory/1148-59-0x0000000000000000-mapping.dmp

Download
memory/1424-78-0x0000000000400000-0x000000000070E000-memory.dmp

Filesize
3.1MB

Download
memory/1424-75-0x00000000002CB000-0x00000000002DC000-memory.dmp

Filesize
68KB

Download
memory/1532-65-0x0000000000000000-mapping.dmp

Download
memory/1536-70-0x0000000000080000-0x0000000000095000-memory.dmp

Filesize
84KB

Download
memory/1536-72-0x0000000000080000-0x0000000000095000-memory.dmp

Filesize
84KB

Download
memory/1536-73-0x0000000000089A6B-mapping.dmp

Download
memory/1536-79-0x0000000000080000-0x0000000000095000-memory.dmp

Filesize
84KB

Download
memory/1536-80-0x0000000000080000-0x0000000000095000-memory.dmp

Filesize
84KB

Download
memory/1988-62-0x0000000000000000-mapping.dmp

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Matrix ATT&CK v6

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Downloads