ostap | 5c0a79af89a9383292db76652a6cfee60bc0509dc30250528f3c40002fc0f691

General

Target

361138996b8beb0a2b93fc76b01de114.xlsm.vir.xlsm
Size

387KB
MD5

361138996b8beb0a2b93fc76b01de114
SHA1

93cde623489e7174d5d116c5fb0b35de691c78d8
SHA256

5c0a79af89a9383292db76652a6cfee60bc0509dc30250528f3c40002fc0f691
SHA512

3de36e66b73f20d601b0c074de22e6f3edaca6502c956f7cac412d2a6642bf9112195008c0ab551cf34c428a4604f134a9fd4ffdd52c609b786fe3a63cad5bd7

Score

10^/10

Malware Config

Signatures

Ostap JavaScript Downloader 1 IoCs

Ostap is a JavaScript downloader that's been active since 2016. It's used to deliver several families, inluding TrickBot

resource	yara_rule
behavioral2/files/0x000500000001ab6a-327.dat	family_ostap

Process spawned unexpected child process 1 IoCs

This typically indicates the parent process was compromised via an exploit or macro.

description	pid	pid_target	Process	procid_target
Parent C:\Program Files\Microsoft Office\Root\Office16\EXCEL.EXE is not expected to spawn this process	1404	368	explorer.exe	68

ostap
Ostap is a JS downloader, used to deliver other families.
downloader ostap

Blocklisted process makes network request 1 IoCs

flow	pid	Process
43	696	WScript.exe

Process spawned suspicious child process 1 IoCs

This child process is typically not spawned unless (for example) the parent process crashes. This typically indicates the parent process was unsuccessfully compromised.

description	pid	pid_target	Process	procid_target
Parent C:\Program Files\Microsoft Office\Root\Office16\EXCEL.EXE is not expected to spawn this process	1236	368	DW20.EXE	68

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

System Information Discovery
T1082

Checks processor information in registry 2 TTPs 3 IoCs

Processor information is often read in order to detect sandboxing environments.

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key opened	\REGISTRY\MACHINE\Hardware\Description\System\CentralProcessor\0	EXCEL.EXE
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\~MHz	EXCEL.EXE
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\ProcessorNameString	EXCEL.EXE

Enumerates system info in registry 2 TTPs 3 IoCs

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key opened	\REGISTRY\MACHINE\Hardware\Description\System\BIOS	EXCEL.EXE
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\BIOS\SystemFamily	EXCEL.EXE
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\BIOS\SystemSKU	EXCEL.EXE

Modifies registry class 1 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-369956170-74428499-1628131376-1000_Classes\Local Settings	explorer.exe

Suspicious behavior: AddClipboardFormatListener 1 IoCs

pid	Process
368	EXCEL.EXE

Suspicious behavior: EnumeratesProcesses 4 IoCs

pid	Process
368	EXCEL.EXE
368	EXCEL.EXE
1584	dwwin.exe
1584	dwwin.exe

Suspicious use of SetWindowsHookEx 14 IoCs

pid	Process
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE
368	EXCEL.EXE

Suspicious use of WriteProcessMemory 10 IoCs

description	pid	Process	procid_target
PID 368 wrote to memory of 1404	368	EXCEL.EXE	71
PID 368 wrote to memory of 1404	368	EXCEL.EXE	71
PID 1716 wrote to memory of 696	1716	explorer.exe	73
PID 1716 wrote to memory of 696	1716	explorer.exe	73
PID 368 wrote to memory of 2060	368	EXCEL.EXE	74
PID 368 wrote to memory of 2060	368	EXCEL.EXE	74
PID 368 wrote to memory of 1236	368	EXCEL.EXE	75
PID 368 wrote to memory of 1236	368	EXCEL.EXE	75
PID 1236 wrote to memory of 1584	1236	DW20.EXE	76
PID 1236 wrote to memory of 1584	1236	DW20.EXE	76

C:\Program Files\Microsoft Office\Root\Office16\EXCEL.EXE
"C:\Program Files\Microsoft Office\Root\Office16\EXCEL.EXE" "C:\Users\Admin\AppData\Local\Temp\361138996b8beb0a2b93fc76b01de114.xlsm.vir.xlsm"
1⤵
- Checks processor information in registry
- Enumerates system info in registry
- Suspicious behavior: AddClipboardFormatListener
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of SetWindowsHookEx
- Suspicious use of WriteProcessMemory
PID:368
- C:\Windows\explorer.exe
  "C:\Windows\explorer.exe" "C:\Users\Admin\AppData\Roaming\Microsoft\Excel\XLSTART\..\..\..\..\..\5034t.dert.jse"
  2⤵
  - Process spawned unexpected child process
  PID:1404
- C:\Windows\splwow64.exe
  C:\Windows\splwow64.exe 12288
  2⤵
  PID:2060
- C:\Program Files\Microsoft Office\root\vfs\ProgramFilesCommonX64\Microsoft Shared\DW\DW20.EXE
  "C:\Program Files\Microsoft Office\root\vfs\ProgramFilesCommonX64\Microsoft Shared\DW\DW20.EXE" -x -s 4352
  2⤵
  - Process spawned suspicious child process
  - Suspicious use of WriteProcessMemory
  PID:1236
- - C:\Windows\system32\dwwin.exe
    C:\Windows\system32\dwwin.exe -x -s 4352
    3⤵
    - Suspicious behavior: EnumeratesProcesses
    PID:1584

C:\Windows\explorer.exe
C:\Windows\explorer.exe /factory,{75dff2b7-6936-4c06-a8bb-676a7b00b24b} -Embedding
1⤵
- Modifies registry class
- Suspicious use of WriteProcessMemory
PID:1716
- C:\Windows\System32\WScript.exe
  "C:\Windows\System32\WScript.exe" "C:\Users\Admin\5034t.dert.jse"
  2⤵
  - Blocklisted process makes network request
  PID:696

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Credential Access

Discovery

Query Registry

2

T1012

System Information Discovery

3

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

memory/368-121-0x00000163104A0000-0x00000163104A2000-memory.dmp

Filesize
8KB

Download
memory/368-263-0x0000016325E10000-0x0000016325E14000-memory.dmp

Filesize
16KB

Download
memory/368-118-0x00007FFF65860000-0x00007FFF65870000-memory.dmp

Filesize
64KB

Download
memory/368-120-0x00000163104A0000-0x00000163104A2000-memory.dmp

Filesize
8KB

Download
memory/368-119-0x00000163104A0000-0x00000163104A2000-memory.dmp

Filesize
8KB

Download
memory/368-115-0x00007FFF65860000-0x00007FFF65870000-memory.dmp

Filesize
64KB

Download
memory/368-127-0x00007FFF65860000-0x00007FFF65870000-memory.dmp

Filesize
64KB

Download
memory/368-117-0x00007FFF65860000-0x00007FFF65870000-memory.dmp

Filesize
64KB

Download
memory/368-116-0x00007FFF65860000-0x00007FFF65870000-memory.dmp

Filesize
64KB

Download

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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Downloads