formbook | 399013dde1bc2ce10effb58c3e970c8bf82d597c3b5f606a0e4ad79567515b2c

General

Target
arirrylhnq8.exe
Size 907KB
Sample200804-4ezy4g6qqe
SHA256 399013dde1bc2ce10effb58c3e970c8bf82d597c3b5f606a0e4ad79567515b2c
MD5 1c3259e07070105f89c38394ae68557b
SHA1 81a72d2374f444c9998b5bc423ec06d47078208f
SHA512 452f8c23071cb81abed5472e75d586bab87bb0469649b2c2259ea0266c05e6392952d2d1d98524e8a21455f475a0ef5a5e12ca1f8bd3813e13f438b62a7c0437
MD5 SHA1 SHA512

Score

10^/10

rat trojan spyware stealer formbook evasion persistence

Malware Config

Signatures

Suspicious behavior: EnumeratesProcesses 30 IoCs

pid	Process
1060	arirrylhnq8.exe
1124	arirrylhnq8.exe
1124	arirrylhnq8.exe
1124	arirrylhnq8.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe

Suspicious use of AdjustPrivilegeToken 3 IoCs

description	pid	Process
Token: SeDebugPrivilege	1124	arirrylhnq8.exe
Token: SeDebugPrivilege	1068	chkdsk.exe
Token: SeShutdownPrivilege	1324	Explorer.EXE

Reads user/profile data of web browsers 2 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
spyware

Data from Local System
T1005

Credentials in Files
T1081

Enumerates system info in registry 2 TTPs 1 IoCs

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\Identifier	chkdsk.exe

Suspicious behavior: MapViewOfSection 9 IoCs

pid	Process
1060	arirrylhnq8.exe
1124	arirrylhnq8.exe
1124	arirrylhnq8.exe
1124	arirrylhnq8.exe
1124	arirrylhnq8.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe
1068	chkdsk.exe

Suspicious use of SetThreadContext 4 IoCs

description	pid	Process	procid_target
PID 1060 set thread context of 1124	1060	arirrylhnq8.exe	24
PID 1124 set thread context of 1324	1124	arirrylhnq8.exe	20
PID 1124 set thread context of 1324	1124	arirrylhnq8.exe	20
PID 1068 set thread context of 1324	1068	chkdsk.exe	20

Checks whether UAC is enabled 1 TTPs 1 IoCs

evasion trojan

System Information Discovery

T1082

description	ioc	Process
Key value queried	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA	Explorer.EXE

Adds Run key to start application 2 TTPs 2 IoCs

persistence

Registry Run Keys / Startup Folder

T1060

Modify Registry

T1112

description	ioc	Process
Key created	\Registry\Machine\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run	chkdsk.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run\ZRUXZL40W6 = "C:\\Program Files (x86)\\Bbdf\\ms3fvhp.exe"	chkdsk.exe

Modifies Internet Explorer settings 1 TTPs 1 IoCs

adware spyware

Modify Registry

T1112

description	ioc	Process
Key created	\Registry\User\S-1-5-21-1131729243-447456001-3632642222-1000\SOFTWARE\Microsoft\Internet Explorer\IntelliForms\Storage2	chkdsk.exe

Suspicious use of WriteProcessMemory 17 IoCs

description	pid	Process	procid_target
PID 1060 wrote to memory of 1124	1060	arirrylhnq8.exe	24
PID 1060 wrote to memory of 1124	1060	arirrylhnq8.exe	24
PID 1060 wrote to memory of 1124	1060	arirrylhnq8.exe	24
PID 1060 wrote to memory of 1124	1060	arirrylhnq8.exe	24
PID 1324 wrote to memory of 1068	1324	Explorer.EXE	25
PID 1324 wrote to memory of 1068	1324	Explorer.EXE	25
PID 1324 wrote to memory of 1068	1324	Explorer.EXE	25
PID 1324 wrote to memory of 1068	1324	Explorer.EXE	25
PID 1068 wrote to memory of 1424	1068	chkdsk.exe	26
PID 1068 wrote to memory of 1424	1068	chkdsk.exe	26
PID 1068 wrote to memory of 1424	1068	chkdsk.exe	26
PID 1068 wrote to memory of 1424	1068	chkdsk.exe	26
PID 1068 wrote to memory of 1820	1068	chkdsk.exe	29
PID 1068 wrote to memory of 1820	1068	chkdsk.exe	29
PID 1068 wrote to memory of 1820	1068	chkdsk.exe	29
PID 1068 wrote to memory of 1820	1068	chkdsk.exe	29
PID 1068 wrote to memory of 1820	1068	chkdsk.exe	29

Suspicious use of FindShellTrayWindow 5 IoCs

pid	Process
1324	Explorer.EXE
1324	Explorer.EXE
1324	Explorer.EXE
1324	Explorer.EXE
1324	Explorer.EXE

Suspicious use of SendNotifyMessage 4 IoCs

pid	Process
1324	Explorer.EXE
1324	Explorer.EXE
1324	Explorer.EXE
1324	Explorer.EXE

Formbook Payload 4 IoCs

rat

resource	yara_rule
behavioral1/memory/1124-0-0x0000000000400000-0x0000000000427000-memory.dmp	formbook
behavioral1/memory/1124-0-0x0000000000400000-0x0000000000427000-memory.dmp	formbook
behavioral1/memory/1124-1-0x000000000041C220-mapping.dmp	formbook
behavioral1/memory/1068-3-0x0000000000000000-mapping.dmp	formbook

Drops file in Program Files directory 1 IoCs

description	ioc	Process
File opened for modification	C:\Program Files (x86)\Bbdf\ms3fvhp.exe	chkdsk.exe

Deletes itself 1 IoCs

pid	Process
1424	cmd.exe

Formbook
Formbook is a data stealing malware which is capable of stealing data.
trojan spyware stealer formbook

C:\Windows\Explorer.EXE
C:\Windows\Explorer.EXE
1⤵
- Suspicious use of AdjustPrivilegeToken
- Checks whether UAC is enabled
- Suspicious use of WriteProcessMemory
- Suspicious use of FindShellTrayWindow
- Suspicious use of SendNotifyMessage
PID:1324
- C:\Users\Admin\AppData\Local\Temp\arirrylhnq8.exe
  "C:\Users\Admin\AppData\Local\Temp\arirrylhnq8.exe"
  2⤵
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious behavior: MapViewOfSection
  - Suspicious use of SetThreadContext
  - Suspicious use of WriteProcessMemory
  PID:1060
- - C:\Users\Admin\AppData\Local\Temp\arirrylhnq8.exe
    "C:\Users\Admin\AppData\Local\Temp\arirrylhnq8.exe"
    3⤵
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    - Suspicious behavior: MapViewOfSection
    - Suspicious use of SetThreadContext
    PID:1124
- C:\Windows\SysWOW64\chkdsk.exe
  "C:\Windows\SysWOW64\chkdsk.exe"
  2⤵
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  - Enumerates system info in registry
  - Suspicious behavior: MapViewOfSection
  - Suspicious use of SetThreadContext
  - Adds Run key to start application
  - Modifies Internet Explorer settings
  - Suspicious use of WriteProcessMemory
  - Drops file in Program Files directory
  PID:1068
- - C:\Windows\SysWOW64\cmd.exe
    /c del "C:\Users\Admin\AppData\Local\Temp\arirrylhnq8.exe"
    3⤵
    - Deletes itself
    PID:1424
- - C:\Program Files\Mozilla Firefox\Firefox.exe
    "C:\Program Files\Mozilla Firefox\Firefox.exe"
    3⤵
    PID:1820

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Registry Run Keys / Startup Folder

1

T1060

Privilege Escalation

Defense Evasion

Modify Registry

2

T1112

Credential Access

Credentials in Files

1

T1081

Discovery

Query Registry

1

T1012

System Information Discovery

2

T1082

Lateral Movement

Collection

Data from Local System

1

T1005

Command and Control

Exfiltration

Impact

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Downloads

memory/1068-4-0x0000000000870000-0x0000000000877000-memory.dmp

Download

memory/1068-6-0x0000000003270000-0x0000000003375000-memory.dmp

Download

memory/1068-7-0x0000000076C90000-0x0000000076C9C000-memory.dmp

Download

memory/1068-8-0x00000000761C0000-0x00000000762DD000-memory.dmp

Download

memory/1068-14-0x0000000003520000-0x000000000365D000-memory.dmp

Download

memory/1124-0-0x0000000000400000-0x0000000000427000-memory.dmp

Download

memory/1324-2-0x0000000007C80000-0x0000000007D5F000-memory.dmp

Download

memory/1820-16-0x000000013FB70000-0x000000013FC03000-memory.dmp

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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Downloads