Malicious PDF — malware analysis report

Static analysis result for SHA-256 15d5ed3f6cc3a17b…

MALICIOUS

PDF

69.6 KB Created: 2021-10-01 12:05:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ffbe0fc08064a8c0fce8184366a501e6 SHA-1: 0bc523f5f3796e6562e76d83feb9180e3912197c SHA-256: 15d5ed3f6cc3a17b81f7a857f492430f1090748073b5591994d407b4e82100b7
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier strongly indicates maliciousness, and the structure suggests it's designed to redirect users to potentially harmful sites, possibly for SEO spam or to host further malicious content. No scripts were extracted, but the URL structure and heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://crewmak.ru/uplcv?utm_term=adb+driver+xiaomi PDF link annotation
    • http://ever-pioneer.com/upload/files/48145228799.pdfIn PDF document text
    • http://yuqiaohome.com/uploads/files/202109161937024175.pdfIn PDF document text
    • https://locktactyuma.com/ckfinder/userfiles/files/mufibazesemofedagetux.pdfIn PDF document text
    • http://ixtvs.de/_upload_bilder/_filemanager/file/viriwetodalib.pdfIn PDF document text
    • http://pnktools-th.org/ckfinder/userfiles/files/78142942626.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612ecef5479e7---kazukatatuvoxebo.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/ladomubepurajizilegugipe.pdfIn PDF document text
    • https://aokman-drive.com/d/files/jinax.pdfIn PDF document text
    • https://comfortinnbarrie.com/phpsites/vertical_living/uploads/file/91868891356.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/d3f2c83d52ccb420a44654e78d9dca57/5183001024.pdfIn PDF document text
    • https://htchninc.com/d/files/62889369816.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/4207731867.pdfIn PDF document text
    • http://anninh247.info/upload/files/lekabibimezap.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/67297017107.pdfIn PDF document text
    • https://mamap.in/ci/userfiles/files/9058831105.pdfIn PDF document text
    • http://scro.ru/pic/file/16965832664.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/1cf11b6b7777b05eb89655ee7b470682/66939008389.pdfIn PDF document text
    • http://vrieshorst.nl/images/uploads/file/xovavojuvawawa.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614e22d427bcb---zazewekeze.pdfIn PDF document text
    • https://stotex.rs/files/wubijivabuwavekudex.pdfIn PDF document text
    • https://pfhotel.gr/ckfinder/userfiles/files/53214477504.pdfIn PDF document text
    • http://mmbc.cz/_data/user_files/file/vexemositokisofexowaji.pdfIn PDF document text
    • http://an-ocn.ru/ckfinder/userfiles/files/metoxupajudupat.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b00b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB00B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c81d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC81D 16416 bytes
SHA-256: 79013de9f75e310751771d7c73ae0edc4342bf0a99a4aef4988613c6b2c6456e
font_02_sfnt_off0000f21b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21B 10280 bytes
SHA-256: 88e21d270bb6ffa1cdf7fd08a1f8d9f58d23580351713d811ccef53d786eddb3