tofsee | 4ffd8a5153b680b86b258bde87319885182c5e078cc0c0b16ab64009f7c69979

General

Target

file.exe
Size

276KB
MD5

8861c3fedd83a41ca2637215c3bea553
SHA1

9394b1527afa8de77c962e0895c681819cb2a529
SHA256

4ffd8a5153b680b86b258bde87319885182c5e078cc0c0b16ab64009f7c69979
SHA512

f1e21803aee16d146737284e491685e084b3d0a65e42986d4a4c5233f4860d309e7aa12cd8516baca7ad9384dd8ac43f67fdd2866e7e4b453b184e458eb87653
SSDEEP

3072:exZL86CsL1KL6+tq5qt0OETP2F4HaNMX027CP1JTJbLCrhIh3eGjMgG1ao5Lk:NVsLML6+nt07J8OrOHNPSuRjMgU

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:

ynbyrxtw.exe

pid process

4260 ynbyrxtw.exe
Modifies Windows Firewall 1 TTPs 1 IoCs
evasion

Modify Existing Service
T1031

Processes:

netsh.exe

pid process

4488 netsh.exe

pid	process
4260	ynbyrxtw.exe

pid	process
4488	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\zdofobfr\ImagePath = "C:\\Windows\\SysWOW64\\zdofobfr\\ynbyrxtw.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-1-5-21-2629973501-4017243118-3254762364-1000\Control Panel\International\Geo\Nation file.exe
Suspicious use of SetThreadContext 1 IoCs

Processes:

ynbyrxtw.exe

description pid process target process

PID 4260 set thread context of 2188 4260 ynbyrxtw.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

2636 sc.exe
2364 sc.exe
2836 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

4148 1688 WerFault.exe file.exe
3604 4260 WerFault.exe ynbyrxtw.exe

description	ioc	process
Key value queried	\REGISTRY\USER\S-1-5-21-2629973501-4017243118-3254762364-1000\Control Panel\International\Geo\Nation	file.exe

description	pid	process	target process
PID 4260 set thread context of 2188	4260	ynbyrxtw.exe	svchost.exe

pid	process
2636	sc.exe
2364	sc.exe
2836	sc.exe

pid	pid_target	process	target process
4148	1688	WerFault.exe	file.exe
3604	4260	WerFault.exe	ynbyrxtw.exe

Suspicious use of WriteProcessMemory 23 IoCs

Processes:

file.exeynbyrxtw.exe

description	pid	process	target process
PID 1688 wrote to memory of 2264	1688	file.exe	cmd.exe
PID 1688 wrote to memory of 2264	1688	file.exe	cmd.exe
PID 1688 wrote to memory of 2264	1688	file.exe	cmd.exe
PID 1688 wrote to memory of 4964	1688	file.exe	cmd.exe
PID 1688 wrote to memory of 4964	1688	file.exe	cmd.exe
PID 1688 wrote to memory of 4964	1688	file.exe	cmd.exe
PID 1688 wrote to memory of 2636	1688	file.exe	sc.exe
PID 1688 wrote to memory of 2636	1688	file.exe	sc.exe
PID 1688 wrote to memory of 2636	1688	file.exe	sc.exe
PID 1688 wrote to memory of 2364	1688	file.exe	sc.exe
PID 1688 wrote to memory of 2364	1688	file.exe	sc.exe
PID 1688 wrote to memory of 2364	1688	file.exe	sc.exe
PID 1688 wrote to memory of 2836	1688	file.exe	sc.exe
PID 1688 wrote to memory of 2836	1688	file.exe	sc.exe
PID 1688 wrote to memory of 2836	1688	file.exe	sc.exe
PID 1688 wrote to memory of 4488	1688	file.exe	netsh.exe
PID 1688 wrote to memory of 4488	1688	file.exe	netsh.exe
PID 1688 wrote to memory of 4488	1688	file.exe	netsh.exe
PID 4260 wrote to memory of 2188	4260	ynbyrxtw.exe	svchost.exe
PID 4260 wrote to memory of 2188	4260	ynbyrxtw.exe	svchost.exe
PID 4260 wrote to memory of 2188	4260	ynbyrxtw.exe	svchost.exe
PID 4260 wrote to memory of 2188	4260	ynbyrxtw.exe	svchost.exe
PID 4260 wrote to memory of 2188	4260	ynbyrxtw.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:1688

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\zdofobfr\
2⤵
PID:2264

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\ynbyrxtw.exe" C:\Windows\SysWOW64\zdofobfr\
2⤵
PID:4964

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" create zdofobfr binPath= "C:\Windows\SysWOW64\zdofobfr\ynbyrxtw.exe /d\"C:\Users\Admin\AppData\Local\Temp\file.exe\"" type= own start= auto DisplayName= "wifi support"
2⤵
- Launches sc.exe
PID:2636

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" description zdofobfr "wifi internet conection"
2⤵
- Launches sc.exe
PID:2364

C:\Windows\SysWOW64\sc.exe
"C:\Windows\System32\sc.exe" start zdofobfr
2⤵
- Launches sc.exe
PID:2836

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:4488

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -u -p 1688 -s 1036
2⤵
- Program crash
PID:4148

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 188 -p 1688 -ip 1688
1⤵
PID:788

C:\Windows\SysWOW64\zdofobfr\ynbyrxtw.exe
C:\Windows\SysWOW64\zdofobfr\ynbyrxtw.exe /d"C:\Users\Admin\AppData\Local\Temp\file.exe"
1⤵
- Executes dropped EXE
- Suspicious use of SetThreadContext
- Suspicious use of WriteProcessMemory
PID:4260

C:\Windows\SysWOW64\svchost.exe
svchost.exe
2⤵
- Sets service image path in registry
PID:2188

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -u -p 4260 -s 528
2⤵
- Program crash
PID:3604

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 444 -p 4260 -ip 4260
1⤵
PID:2744

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\ynbyrxtw.exe
Filesize
13.6MB

MD5
1bbab25ed7b74888765956cfcabe5df4

SHA1
215a40a12494ccf963a9bd32e8e45fafa59dd0cb

SHA256
9d7f26e533bdfb97ca4f449693fa49398b283a2bf30385142cfc240878ce54d8

SHA512
4ab8bd0afb000115a2b647511d38d309736009faf3b9a3df889fa838ba00e4c58e2312092c43835c8033538c1959178807fb84b634dc86d679bc8319f391ffd3

Download Submit
C:\Windows\SysWOW64\zdofobfr\ynbyrxtw.exe
Filesize
13.6MB

MD5
1bbab25ed7b74888765956cfcabe5df4

SHA1
215a40a12494ccf963a9bd32e8e45fafa59dd0cb

SHA256
9d7f26e533bdfb97ca4f449693fa49398b283a2bf30385142cfc240878ce54d8

SHA512
4ab8bd0afb000115a2b647511d38d309736009faf3b9a3df889fa838ba00e4c58e2312092c43835c8033538c1959178807fb84b634dc86d679bc8319f391ffd3

Download Submit
memory/1688-133-0x0000000000580000-0x0000000000593000-memory.dmp

Filesize
76KB

Download
memory/1688-134-0x0000000000400000-0x000000000044A000-memory.dmp

Filesize
296KB

Download
memory/1688-144-0x0000000000400000-0x000000000044A000-memory.dmp

Filesize
296KB

Download
memory/1688-132-0x0000000000637000-0x000000000064C000-memory.dmp

Filesize
84KB

Download
memory/1688-141-0x0000000000580000-0x0000000000593000-memory.dmp

Filesize
76KB

Download
memory/2188-146-0x00000000009D0000-0x00000000009E5000-memory.dmp

Filesize
84KB

Download
memory/2188-152-0x00000000009D0000-0x00000000009E5000-memory.dmp

Filesize
84KB

Download
memory/2188-145-0x0000000000000000-mapping.dmp

Download
memory/2188-151-0x00000000009D0000-0x00000000009E5000-memory.dmp

Filesize
84KB

Download
memory/2264-135-0x0000000000000000-mapping.dmp

Download
memory/2364-139-0x0000000000000000-mapping.dmp

Download
memory/2636-138-0x0000000000000000-mapping.dmp

Download
memory/2836-140-0x0000000000000000-mapping.dmp

Download
memory/4260-149-0x00000000005C2000-0x00000000005D7000-memory.dmp

Filesize
84KB

Download
memory/4260-150-0x0000000000400000-0x000000000044A000-memory.dmp

Filesize
296KB

Download
memory/4488-142-0x0000000000000000-mapping.dmp

Download
memory/4964-136-0x0000000000000000-mapping.dmp

Download

Analysis

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