Nasreddine Bencherchali
32 lines
1.1 KiB
YAML
32 lines
1.1 KiB
YAML
title: Binary Padding - MacOS
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id: 95361ce5-c891-4b0a-87ca-e24607884a96
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status: test
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description: Adversaries may use binary padding to add junk data and change the on-disk representation of malware. This rule detect using dd and truncate to add a junk data to file.
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references:
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- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1027.001/T1027.001.md
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- https://linux.die.net/man/1/truncate
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- https://linux.die.net/man/1/dd
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author: 'Igor Fits, Mikhail Larin, oscd.community'
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date: 2020-10-19
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modified: 2023-02-17
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tags:
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- attack.stealth
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- attack.t1027.001
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logsource:
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product: macos
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category: process_creation
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detection:
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selection_truncate:
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Image|endswith: '/truncate'
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CommandLine|contains: '-s +'
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selection_dd:
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Image|endswith: '/dd'
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CommandLine|contains:
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- 'if=/dev/zero' # if input is not /dev/zero, then there is no null padding
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- 'if=/dev/random' # high-quality random data
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- 'if=/dev/urandom' # low-quality random data
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condition: 1 of selection_*
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falsepositives:
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- Legitimate script work
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level: high
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