There is no description at this point.
https://arielkoren.com/blog/2016/11/02/nymaim-deep-technical-dive-adventures-in-evasive-malware/ |
https://public.gdatasoftware.com/Web/Landingpages/DE/GI-Spring2014/slides/004_plohmann.pdf |
https://github.com/coldshell/Malware-Scripts/tree/master/Nymaim |
https://www.cert.pl/en/news/single/nymaim-revisited/ |
https://bitbucket.org/daniel_plohmann/idapatchwork |
rule win_nymaim_auto {
meta:
author = "Felix Bilstein - yara-signator at cocacoding dot com"
date = "2018-11-23"
version = "1"
description = "autogenerated rule brought to you by yara-signator"
tool = "yara-signator 0.1a"
malpedia_reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.nymaim"
malpedia_version = "20180607"
malpedia_license = "CC BY-NC-SA 4.0"
malpedia_sharing = "TLP:WHITE"
/* DISCLAIMER
* The strings used in this rule have been automatically selected from the
* disassembly of memory dumps and unpacked files, using yara-signator.
* The code and documentation / approach will be published in the near future here:
* https://github.com/fxb-cocacoding/yara-signator
* As Malpedia is used as data source, please note that for a given
* number of families, only single samples are documented.
* This likely impacts the degree of generalization these rules will offer.
* Take the described generation method also into consideration when you
* apply the rules in your use cases and assign them confidence levels.
*/
strings:
$sequence_0 = { 89d8 01c8 31d2 f7f7 }
// n = 4, score = 10000
// 89d8 | mov eax, ebx
// 01c8 | add eax, ecx
// 31d2 | xor edx, edx
// f7f7 | div edi
$sequence_1 = { 31d2 f7f7 92 31d2 }
// n = 4, score = 10000
// 31d2 | xor edx, edx
// f7f7 | div edi
// 92 | xchg eax, edx
// 31d2 | xor edx, edx
$sequence_2 = { 89e5 57 53 56 }
// n = 4, score = 10000
// 89e5 | mov ebp, esp
// 57 | push edi
// 53 | push ebx
// 56 | push esi
$sequence_3 = { 01c8 31d2 f7f7 92 }
// n = 4, score = 10000
// 01c8 | add eax, ecx
// 31d2 | xor edx, edx
// f7f7 | div edi
// 92 | xchg eax, edx
$sequence_4 = { f7f7 92 31d2 bf64000000 }
// n = 4, score = 10000
// f7f7 | div edi
// 92 | xchg eax, edx
// 31d2 | xor edx, edx
// bf64000000 | mov edi, 0x64
$sequence_5 = { 31d2 f7f7 92 31d2 bf64000000 }
// n = 5, score = 10000
// 31d2 | xor edx, edx
// f7f7 | div edi
// 92 | xchg eax, edx
// 31d2 | xor edx, edx
// bf64000000 | mov edi, 0x64
$sequence_6 = { 01c8 31d2 f7f7 92 31d2 }
// n = 5, score = 10000
// 01c8 | add eax, ecx
// 31d2 | xor edx, edx
// f7f7 | div edi
// 92 | xchg eax, edx
// 31d2 | xor edx, edx
$sequence_7 = { 55 89e5 57 53 56 }
// n = 5, score = 10000
// 55 | push ebp
// 89e5 | mov ebp, esp
// 57 | push edi
// 53 | push ebx
// 56 | push esi
$sequence_8 = { 89d8 01c8 31d2 f7f7 92 }
// n = 5, score = 10000
// 89d8 | mov eax, ebx
// 01c8 | add eax, ecx
// 31d2 | xor edx, edx
// f7f7 | div edi
// 92 | xchg eax, edx
$sequence_9 = { 89d8 01c8 31d2 f7f7 92 31d2 }
// n = 6, score = 10000
// 89d8 | mov eax, ebx
// 01c8 | add eax, ecx
// 31d2 | xor edx, edx
// f7f7 | div edi
// 92 | xchg eax, edx
// 31d2 | xor edx, edx
condition:
7 of them
}