YARA · Malpedia signator rules
MALPEDIA_Win_Mailto_Auto
autogenerated rule brought to you by yara-signator
- Author
- Felix Bilstein - yara-signator at cocacoding dot com
- Date
- 2026-05-04
- Modified
- 2026-05-18
- Score / Quality
- 75 / 75
What this rule detects
autogenerated rule brought to you by yara-signator
Associated malware family: Mailto.
It defines 10 patterns (0 text, 10 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
win-mailto-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Mailto_Auto : FILE
{
meta:
= "autogenerated rule brought to you by yara-signator"
= "Felix Bilstein - yara-signator at cocacoding dot com"
= "77746f51-fc1c-50cd-a4af-268d4a5b9d6b"
= "2026-05-04"
= "2026-05-18"
= "https://malpedia.caad.fkie.fraunhofer.de/details/win.mailto"
= "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.mailto_auto.yar#L1-L134"
= "N/A"
= "53e3ddf0c82c6285bb2fdbc99e3b02c5febe1a13e39cac446d5a6487b03a6443"
= 75
= 75
= "FILE"
= "1"
= "yara-signator v0.6.0"
= "callsandjumps;datarefs;binvalue"
= "20260422"
= "a182e35da64e6d71cb55f125c4d4225196523f14"
= "20260504"
= "CC BY-SA 4.0"
= "TLP:WHITE"
strings:
$sequence_0 = { 56 e8???????? 83c40c 85c0 75e7 5f 5e }
$sequence_1 = { 68dee412a3 56 894134 e8???????? 8b0d???????? 689a8f3aca 56 }
$sequence_2 = { 5e 85c9 890f 5b 0f95c0 5f c3 }
$sequence_3 = { c744246474000000 e8???????? 8d4c2414 51 56 8b4030 ffd0 }
$sequence_4 = { e8???????? 83c444 6a00 6841db0100 ffb424b0000000 ffb424b0000000 e8???????? }
$sequence_5 = { 23c8 8bc1 c1e01a 29442420 8b442424 03c1 89442424 }
$sequence_6 = { eb08 e8???????? 8b4048 8d4c2410 51 ffd0 880437 }
$sequence_7 = { 33d0 03743c2c 8bc3 03742424 83c704 c1c802 33d0 }
$sequence_8 = { 8d2c8d00000000 23e9 8b4c2430 81f1ffffff03 f7d1 8bc1 8bdd }
$sequence_9 = { ffb424d0000000 89442430 ffb424d0000000 89542438 e8???????? 6a00 6841db0100 }
condition:
7 of them and filesize < 180224
}
Strings (10 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $sequence_0 | hex | { 56 e8???????? 83c40c 85c0 75e7 5f 5e } | |
| $sequence_1 | hex | { 68dee412a3 56 894134 e8???????? 8b0d???????? 689a8f3aca 56 } | |
| $sequence_2 | hex | { 5e 85c9 890f 5b 0f95c0 5f c3 } | |
| $sequence_3 | hex | { c744246474000000 e8???????? 8d4c2414 51 56 8b4030 ffd0 } | |
| $sequence_4 | hex | { e8???????? 83c444 6a00 6841db0100 ffb424b0000000 ffb424b0000000 e8???????? } | |
| $sequence_5 | hex | { 23c8 8bc1 c1e01a 29442420 8b442424 03c1 89442424 } | |
| $sequence_6 | hex | { eb08 e8???????? 8b4048 8d4c2410 51 ffd0 880437 } | |
| $sequence_7 | hex | { 33d0 03743c2c 8bc3 03742424 83c704 c1c802 33d0 } | |
| $sequence_8 | hex | { 8d2c8d00000000 23e9 8b4c2430 81f1ffffff03 f7d1 8bc1 8bdd } | |
| $sequence_9 | hex | { ffb424d0000000 89442430 ffb424d0000000 89542438 e8???????? 6a00 6841db0100 } |
Condition
7 of them and filesize < 180224In plain words (Heuristic)
- The file must be smaller than 180224 (a cheap guard that skips large files).
- At least 7 patterns in the rule must match.
Test this rule in your browser
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Licence & attribution
Author: Felix Bilstein - yara-signator at cocacoding dot com
Source repository: Malpedia signator rules @ c901f97b7d
Licence: Creative Commons Attribution-ShareAlike 4.0 (repository licence)
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: 77746f51-fc1c-50cd-a4af-268d4a5b9d6b
Metadata
| version | 1 |
|---|---|
| tool | yara-signator v0.6.0 |
| signator_config | callsandjumps;datarefs;binvalue |
| malpedia_rule_date | 20260422 |
| malpedia_hash | a182e35da64e6d71cb55f125c4d4225196523f14 |
| malpedia_version | 20260504 |
| malpedia_license | CC BY-SA 4.0 |
| malpedia_sharing | TLP:WHITE |
Tags:FILE
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