Chafer Malware URL Pattern

SIGMA detection rule by Florian Roth (Nextron Systems) · NOASSERTION

Detects HTTP request used by Chafer malware to receive data from its C2.

title: Chafer Malware URL Pattern
id: fb502828-2db0-438e-93e6-801c7548686d
status: test
description: Detects HTTP request used by Chafer malware to receive data from its C2.
references:
    - https://securelist.com/chafer-used-remexi-malware/89538/
author: Florian Roth (Nextron Systems)
date: 2019-01-31
modified: 2024-02-15
tags:
    - attack.command-and-control
    - attack.t1071.001
    - detection.emerging-threats
logsource:
    category: proxy
detection:
    selection:
        c-uri|contains: '/asp.asp\?ui='
    condition: selection
falsepositives:
    - Unknown
level: high

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

281e3074-3b32-456b-8a75-b3e135e8edf6

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

[[ reason ]]

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Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

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What do these messages mean?

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

[[ currentRule.title ]]

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