tofsee | dc0ec3405d05046753c376f33fcd545d03b4781983d4b26103de9419b4334963

General

Target

file.exe
Size

147KB
MD5

245a32c6b70bf744448625ca6d897a57
SHA1

67a7ca7893d555651eb6a38bc22fb9aeacffcec2
SHA256

dc0ec3405d05046753c376f33fcd545d03b4781983d4b26103de9419b4334963
SHA512

aa40eb9fd15e087b346086421b6efdbecc97980868d1404fa32e8ca90a118f3986aef668554ba67badf1dc58ef88c1d688ebe193fed3d3f5dd435d392d3665af
SSDEEP

3072:GFuoANbriTl655frf0zvNDoM2bTXtFW5mMSjv:JbbrHT0zxnoTeo

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:

rlbsvtwf.exe

pid process

2260 rlbsvtwf.exe
Modifies Windows Firewall 1 TTPs 1 IoCs
evasion

Modify Existing Service
T1031

Processes:

netsh.exe

pid process

2448 netsh.exe

pid	process
2260	rlbsvtwf.exe

pid	process
2448	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\cgcxxkm\ImagePath = "C:\\Windows\\SysWOW64\\cgcxxkm\\rlbsvtwf.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:

rlbsvtwf.exe

description pid process target process

PID 2260 set thread context of 2672 2260 rlbsvtwf.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

1308 sc.exe
2428 sc.exe
1108 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

4224 2552 WerFault.exe file.exe
2312 2260 WerFault.exe rlbsvtwf.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 2260 set thread context of 2672	2260	rlbsvtwf.exe	svchost.exe

pid	process
1308	sc.exe
2428	sc.exe
1108	sc.exe

pid	pid_target	process	target process
4224	2552	WerFault.exe	file.exe
2312	2260	WerFault.exe	rlbsvtwf.exe

Suspicious use of WriteProcessMemory 23 IoCs

Processes:

file.exerlbsvtwf.exe

description	pid	process	target process
PID 2552 wrote to memory of 4824	2552	file.exe	cmd.exe
PID 2552 wrote to memory of 4824	2552	file.exe	cmd.exe
PID 2552 wrote to memory of 4824	2552	file.exe	cmd.exe
PID 2552 wrote to memory of 3064	2552	file.exe	cmd.exe
PID 2552 wrote to memory of 3064	2552	file.exe	cmd.exe
PID 2552 wrote to memory of 3064	2552	file.exe	cmd.exe
PID 2552 wrote to memory of 1108	2552	file.exe	sc.exe
PID 2552 wrote to memory of 1108	2552	file.exe	sc.exe
PID 2552 wrote to memory of 1108	2552	file.exe	sc.exe
PID 2552 wrote to memory of 1308	2552	file.exe	sc.exe
PID 2552 wrote to memory of 1308	2552	file.exe	sc.exe
PID 2552 wrote to memory of 1308	2552	file.exe	sc.exe
PID 2552 wrote to memory of 2428	2552	file.exe	sc.exe
PID 2552 wrote to memory of 2428	2552	file.exe	sc.exe
PID 2552 wrote to memory of 2428	2552	file.exe	sc.exe
PID 2552 wrote to memory of 2448	2552	file.exe	netsh.exe
PID 2552 wrote to memory of 2448	2552	file.exe	netsh.exe
PID 2552 wrote to memory of 2448	2552	file.exe	netsh.exe
PID 2260 wrote to memory of 2672	2260	rlbsvtwf.exe	svchost.exe
PID 2260 wrote to memory of 2672	2260	rlbsvtwf.exe	svchost.exe
PID 2260 wrote to memory of 2672	2260	rlbsvtwf.exe	svchost.exe
PID 2260 wrote to memory of 2672	2260	rlbsvtwf.exe	svchost.exe
PID 2260 wrote to memory of 2672	2260	rlbsvtwf.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:2552

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\cgcxxkm\
2⤵
PID:4824

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\rlbsvtwf.exe" C:\Windows\SysWOW64\cgcxxkm\
2⤵
PID:3064

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" create cgcxxkm binPath= "C:\Windows\SysWOW64\cgcxxkm\rlbsvtwf.exe /d\"C:\Users\Admin\AppData\Local\Temp\file.exe\"" type= own start= auto DisplayName= "wifi support"
2⤵
- Launches sc.exe
PID:1108

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" description cgcxxkm "wifi internet conection"
2⤵
- Launches sc.exe
PID:1308

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" start cgcxxkm
2⤵
- Launches sc.exe
PID:2428

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:2448

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -u -p 2552 -s 1044
2⤵
- Program crash
PID:4224

C:\Windows\SysWOW64\cgcxxkm\rlbsvtwf.exe
C:\Windows\SysWOW64\cgcxxkm\rlbsvtwf.exe /d"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Executes dropped EXE
- Suspicious use of SetThreadContext
- Suspicious use of WriteProcessMemory
PID:2260

C:\Windows\SysWOW64\svchost.exe
svchost.exe
2⤵
- Sets service image path in registry
PID:2672

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -u -p 2260 -s 532
2⤵
- Program crash
PID:2312

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 444 -p 2552 -ip 2552
1⤵
PID:952

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 404 -p 2260 -ip 2260
1⤵
PID:2652

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

Modify Registry

1

T1112

Credential Access

Discovery

Query Registry

1

T1012

System Information Discovery

2

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

Loading Replay Monitor...

Downloads

C:\Users\Admin\AppData\Local\Temp\rlbsvtwf.exe
Filesize
14.3MB

MD5
6d4c3c77e9bda64f27befa3c8f8d556a

SHA1
4c0eac5e3c2cd77b80f8661f1df948122dad70fe

SHA256
6bac557abf1c723d8f6443c70ec9ecd8392d559e40343060cf55f43bda9efabd

SHA512
0565078341ed88693eda8d4df3ab1aea49d44bc9137b5874a6f569f9afefe573269ec1f8411a8edd824d9f60712bb7c42dc8bc945783f87b8f33a49628bc4cf3

Download Submit
C:\Windows\SysWOW64\cgcxxkm\rlbsvtwf.exe
Filesize
14.3MB

MD5
6d4c3c77e9bda64f27befa3c8f8d556a

SHA1
4c0eac5e3c2cd77b80f8661f1df948122dad70fe

SHA256
6bac557abf1c723d8f6443c70ec9ecd8392d559e40343060cf55f43bda9efabd

SHA512
0565078341ed88693eda8d4df3ab1aea49d44bc9137b5874a6f569f9afefe573269ec1f8411a8edd824d9f60712bb7c42dc8bc945783f87b8f33a49628bc4cf3

Download Submit
memory/1108-138-0x0000000000000000-mapping.dmp

Download
memory/1308-139-0x0000000000000000-mapping.dmp

Download
memory/2260-149-0x0000000000400000-0x0000000000AD6000-memory.dmp

Filesize
6.8MB

Download
memory/2260-148-0x0000000000E27000-0x0000000000E38000-memory.dmp

Filesize
68KB

Download
memory/2428-140-0x0000000000000000-mapping.dmp

Download
memory/2448-141-0x0000000000000000-mapping.dmp

Download
memory/2552-132-0x0000000000C6D000-0x0000000000C7D000-memory.dmp

Filesize
64KB

Download
memory/2552-133-0x0000000000C30000-0x0000000000C43000-memory.dmp

Filesize
76KB

Download
memory/2552-134-0x0000000000400000-0x0000000000AD6000-memory.dmp

Filesize
6.8MB

Download
memory/2552-143-0x0000000000400000-0x0000000000AD6000-memory.dmp

Filesize
6.8MB

Download
memory/2672-144-0x0000000000000000-mapping.dmp

Download
memory/2672-145-0x0000000000360000-0x0000000000375000-memory.dmp

Filesize
84KB

Download
memory/2672-150-0x0000000000360000-0x0000000000375000-memory.dmp

Filesize
84KB

Download
memory/2672-151-0x0000000000360000-0x0000000000375000-memory.dmp

Filesize
84KB

Download
memory/3064-136-0x0000000000000000-mapping.dmp

Download
memory/4824-135-0x0000000000000000-mapping.dmp

Download

Analysis

Sharing