Overview

overview

10

Static

static

Letter.exe

windows7_x64

10

Letter.exe

windows10-2004_x64

10

Analysis

  • max time kernel
    158s
  • max time network
    173s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20220414-en
  • submitted
    21-05-2022 02:07

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General

  • Target

    Letter.exe

  • Size

    581KB

  • MD5

    6b1a709c8884accc0ba410ef9413a04c

  • SHA1

    bb80dad1518cd8d7bb912b74bcf01c927b45394a

  • SHA256

    439ed702b9700b4bd7ec8877db8d90820176cd183cb888c8be9b14267d3581cc

  • SHA512

    309ef31c93845a36060bd4b69a3d7cfc79bebb518530371846165a49c7dc74069777c09067d3406ee2cb3de94494c8ff31b8ffdeb54f0cd4c6088b6cd6fc16c7

Score
10/10
agentteslacollectionevasionkeyloggerspywarestealertrojan

Malware Config

Extracted

Credentials

  • Protocol:     smtp
  • Host:
    mail.gayaceramic.com
  • Port:
    587
  • Username:
    [email protected]
  • Password:
    2019gaya

Extracted

Family

agenttesla

Credentials

  • Protocol:     smtp
  • Host:
    mail.gayaceramic.com
  • Port:
    587
  • Username:
    [email protected]
  • Password:
    2019gaya

Signatures

  • AgentTesla

    Agent Tesla is a remote access tool (RAT) written in visual basic.

    keyloggertrojanstealerspywareagenttesla
  • AgentTesla Payload 1 IoCs
  • Looks for VirtualBox Guest Additions in registry 2 TTPs
    evasion
  • Looks for VMWare Tools registry key 2 TTPs
    evasion
  • Checks BIOS information in registry 2 TTPs 2 IoCs

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

  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Reads data files stored by FTP clients 2 TTPs

    Tries to access configuration files associated with programs like FileZilla.

    spywarestealer
  • Reads user/profile data of local email clients 2 TTPs

    Email clients store some user data on disk where infostealers will often target it.

    spywarestealer
  • Reads user/profile data of web browsers 2 TTPs

    Infostealers often target stored browser data, which can include saved credentials etc.

    spywarestealer
  • Accesses Microsoft Outlook profiles 1 TTPs 3 IoCs
    collection
  • Maps connected drives based on registry 3 TTPs 2 IoCs

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

  • Suspicious use of SetThreadContext 1 IoCs
  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

  • Creates scheduled task(s) 1 TTPs 1 IoCs

    Schtasks is often used by malware for persistence or to perform post-infection execution.

    persistence
  • Suspicious behavior: EnumeratesProcesses 3 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 11 IoCs
  • outlook_office_path 1 IoCs
  • outlook_win_path 1 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\Letter.exe
    "C:\Users\Admin\AppData\Local\Temp\Letter.exe"
    1⤵
    • Checks BIOS information in registry
    • Checks computer location settings
    • Maps connected drives based on registry
    • Suspicious use of SetThreadContext
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:3568
    • C:\Windows\SysWOW64\schtasks.exe
      "C:\Windows\System32\schtasks.exe" /Create /TN "Updates\hWFpUZAPSDgj" /XML "C:\Users\Admin\AppData\Local\Temp\tmpA817.tmp"
      2⤵
      • Creates scheduled task(s)
      PID:3616
    • C:\Users\Admin\AppData\Local\Temp\Letter.exe
      "C:\Users\Admin\AppData\Local\Temp\Letter.exe"
      2⤵
      • Accesses Microsoft Outlook profiles
      • Suspicious behavior: EnumeratesProcesses
      • Suspicious use of AdjustPrivilegeToken
      • outlook_office_path
      • outlook_win_path
      PID:2484

Network

MITRE ATT&CK Matrix ATT&CK v6

Initial Access

Execution

Scheduled Task

1
T1053

Persistence

Scheduled Task

1
T1053

Privilege Escalation

Scheduled Task

1
T1053

Defense Evasion

Virtualization/Sandbox Evasion

2
T1497

Credential Access

Credentials in Files

3
T1081

Discovery

Query Registry

5
T1012

Virtualization/Sandbox Evasion

2
T1497

System Information Discovery

4
T1082

Peripheral Device Discovery

1
T1120

Lateral Movement

Collection

Data from Local System

3
T1005

Email Collection

1
T1114

Exfiltration

Command and Control

Impact

Replay Monitor

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Downloads

  • C:\Users\Admin\AppData\Local\Temp\tmpA817.tmp
    Filesize

    1KB

    MD5

    b728c23aa5f5218112b49e259c039783

    SHA1

    70f2afe4c06cbab433c0217e5f54cdfe38b44a33

    SHA256

    cba3b96c31d64dfc58dd8cd5a4edb1817c91acbed471ae4f2d52605e4fda6760

    SHA512

    2af7e76cb8ed843ed3fde909c4bad7c0c06fc46a013cb29675d7dbf9533f7e9a4d453a596234ea2d76c369be4cf0f40c8a1d89988968b422db023fe89ab3e649

    Download Submit
  • memory/2484-139-0x0000000000000000-mapping.dmp
    Download
  • memory/2484-140-0x0000000000400000-0x000000000045A000-memory.dmp
    Filesize

    360KB

    Download
  • memory/2484-141-0x0000000006C90000-0x0000000006CE0000-memory.dmp
    Filesize

    320KB

    Download
  • memory/3568-130-0x0000000000D10000-0x0000000000DA8000-memory.dmp
    Filesize

    608KB

    Download
  • memory/3568-131-0x00000000056F0000-0x000000000578C000-memory.dmp
    Filesize

    624KB

    Download
  • memory/3568-132-0x0000000005D40000-0x00000000062E4000-memory.dmp
    Filesize

    5.6MB

    Download
  • memory/3568-133-0x0000000005830000-0x00000000058C2000-memory.dmp
    Filesize

    584KB

    Download
  • memory/3568-134-0x00000000057F0000-0x00000000057FA000-memory.dmp
    Filesize

    40KB

    Download
  • memory/3568-135-0x0000000005A40000-0x0000000005A96000-memory.dmp
    Filesize

    344KB

    Download
  • memory/3568-136-0x0000000009700000-0x0000000009766000-memory.dmp
    Filesize

    408KB

    Download
  • memory/3616-137-0x0000000000000000-mapping.dmp
    Download