There is no description at this point.
https://www.arbornetworks.com/blog/asert/wp-content/uploads/2016/02/ASERT-Threat-Intelligence-Brief-2016-02-Corebot-1.pdf |
https://malwarebreakdown.com/2017/09/11/re-details-malspam-downloads-corebot-banking-trojan/ |
http://blog.deepinstinct.com/2017/11/08/a-deeper-dive-into-corebots-comeback/ |
rule win_corebot_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.corebot"
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 = { 7410 85c0 740c 50 }
// n = 4, score = 10000
// 7410 | je 0x95162c
// 85c0 | test eax, eax
// 740c | je 0x95162c
// 50 | push eax
$sequence_1 = { 895e0c 8b03 894604 83e880 }
// n = 4, score = 10000
// 895e0c | mov dword ptr [esi + 0xc], ebx
// 8b03 | mov eax, dword ptr [ebx]
// 894604 | mov dword ptr [esi + 4], eax
// 83e880 | sub eax, -0x80
$sequence_2 = { 8b03 894604 83e880 894608 }
// n = 4, score = 10000
// 8b03 | mov eax, dword ptr [ebx]
// 894604 | mov dword ptr [esi + 4], eax
// 83e880 | sub eax, -0x80
// 894608 | mov dword ptr [esi + 8], eax
$sequence_3 = { 53 6800001040 6a03 53 }
// n = 4, score = 10000
// 53 | push ebx
// 6800001040 | push 0x40100000
// 6a03 | push 3
// 53 | push ebx
$sequence_4 = { 6800001040 6a03 53 53 }
// n = 4, score = 10000
// 6800001040 | push 0x40100000
// 6a03 | push 3
// 53 | push ebx
// 53 | push ebx
$sequence_5 = { 89461c 8b00 894614 83e880 }
// n = 4, score = 10000
// 89461c | mov dword ptr [esi + 0x1c], eax
// 8b00 | mov eax, dword ptr [eax]
// 894614 | mov dword ptr [esi + 0x14], eax
// 83e880 | sub eax, -0x80
$sequence_6 = { eb10 6800800000 6a00 56 }
// n = 4, score = 10000
// eb10 | jmp 0x96e20b
// 6800800000 | push 0x8000
// 6a00 | push 0
// 56 | push esi
$sequence_7 = { 85c0 7515 8b4624 3b4620 }
// n = 4, score = 10000
// 85c0 | test eax, eax
// 7515 | jne 0x978abf
// 8b4624 | mov eax, dword ptr [esi + 0x24]
// 3b4620 | cmp eax, dword ptr [esi + 0x20]
$sequence_8 = { 85ff 740f 57 ff7508 }
// n = 4, score = 10000
// 85ff | test edi, edi
// 740f | je 0x9532da
// 57 | push edi
// ff7508 | push dword ptr [ebp + 8]
$sequence_9 = { 8b00 894614 83e880 894618 }
// n = 4, score = 10000
// 8b00 | mov eax, dword ptr [eax]
// 894614 | mov dword ptr [esi + 0x14], eax
// 83e880 | sub eax, -0x80
// 894618 | mov dword ptr [esi + 0x18], eax
condition:
7 of them
}