Elise Backdoor Activity

Status: test
Severity: critical
Log source: category process_creation, product windows
Author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects Elise backdoor activity used by APT32

Known false positives

Unlikely

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059.003` Command and Scripting Interpreter: Windows Command Shell

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: Elise Backdoor Activity
id: e507feb7-5f73-4ef6-a970-91bb6f6d744f
status: test
description: Detects Elise backdoor activity used by APT32
references:
    - https://community.rsa.com/community/products/netwitness/blog/2018/02/13/lotus-blossom-continues-asean-targeting
    - https://web.archive.org/web/20200302083912/https://www.accenture.com/t20180127T003755Z_w_/us-en/_acnmedia/PDF-46/Accenture-Security-Dragonfish-Threat-Analysis.pdf
author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2018-01-31
modified: 2023-03-09
tags:
    - attack.g0030
    - attack.g0050
    - attack.s0081
    - attack.execution
    - attack.t1059.003
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection_other_svchost:
        Image|endswith: '\Microsoft\Network\svchost.exe'
    selection_other_del:
        CommandLine|contains|all:
            - '\Windows\Caches\NavShExt.dll'
            - '/c del'
    selection_dll_path:
        CommandLine|endswith:
            - '\AppData\Roaming\MICROS~1\Windows\Caches\NavShExt.dll'
            - '\AppData\Roaming\Microsoft\Windows\Caches\NavShExt.dll'
    selection_dll_function:
        CommandLine|contains: ',Setting'
    condition: 1 of selection_other_* or all of selection_dll_*
falsepositives:
    - Unlikely
level: critical

Stages and Predicates

Stage 0: `condition`

1 of selection_other_* or all of selection_dll_*

Stage 1: `selection_other_svchost`

selection_other_svchost:
    Image|endswith: '\Microsoft\Network\svchost.exe'

Stage 2: `selection_other_del`

selection_other_del:
    CommandLine|contains|all:
        - '\Windows\Caches\NavShExt.dll'
        - '/c del'

Stage 3: `selection_dll_path`

selection_dll_path:
    CommandLine|endswith:
        - '\AppData\Roaming\MICROS~1\Windows\Caches\NavShExt.dll'
        - '\AppData\Roaming\Microsoft\Windows\Caches\NavShExt.dll'

Stage 4: `selection_dll_function`

selection_dll_function:
    CommandLine|contains: ',Setting'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	ends_with	`\AppData\Roaming\MICROS~1\Windows\Caches\NavShExt.dll` `\AppData\Roaming\Microsoft\Windows\Caches\NavShExt.dll`	`field:"CommandLine" kind:ends_with`
`CommandLine`	match	`,Setting` `/c del` `\Windows\Caches\NavShExt.dll`	`field:"CommandLine" kind:match`
`Image`	ends_with	`\Microsoft\Network\svchost.exe`	`field:"Image" kind:ends_with value:"\Microsoft\Network\svchost.exe"`

Elise Backdoor Activity

Known false positives

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection_other_svchost

Stage 2: selection_other_del

Stage 3: selection_dll_path

Stage 4: selection_dll_function

Indicators

Stage 0: `condition`

Stage 1: `selection_other_svchost`

Stage 2: `selection_other_del`

Stage 3: `selection_dll_path`

Stage 4: `selection_dll_function`