29 lines
No EOL
1 KiB
Text
29 lines
No EOL
1 KiB
Text
/*
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Version 0.0.3 2015/02/15
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Source code put in public domain by Didier Stevens, no Copyright
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https://DidierStevens.com
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Use at your own risk
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Shortcomings, or todo's ;-) :
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Constant 0x06 in the condition is the minimum length of the string matched by regex $b.
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Ideally, this should be an expression and not a constant, for example len($d).
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History:
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2014/12/23: start
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2015/01/01: continued
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2015/01/11: changed regex to \W
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2015/02/15: replaced regex \W with \b (available in YARA 3.3.0)
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*/
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rule JPEG_EXIF_Contains_eval
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{
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meta:
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author = "Didier Stevens (https://DidierStevens.com)"
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description = "Detect eval function inside JPG EXIF header (http://blog.sucuri.net/2013/07/malware-hidden-inside-jpg-exif-headers.html)"
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method = "Detect JPEG file and EXIF header ($a) and eval function ($b) inside EXIF data"
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strings:
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$a = {FF E1 ?? ?? 45 78 69 66 00}
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$b = /\beval\s*\(/
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condition:
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uint16be(0x00) == 0xFFD8 and $a and $b in (@a + 0x12 .. @a + 0x02 + uint16be(@a + 0x02) - 0x06)
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} |