Malicious PDF — malware analysis report

Static analysis result for SHA-256 53cc3012fff7bf54…

MALICIOUS

PDF

78.4 KB Created: 2021-06-23 06:57:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 50ff89cd96b1618e86cbcec020d0f40f SHA-1: f7b478d10f13a21a15e2f317ad391cda3156b280 SHA-256: 53cc3012fff7bf542a556617f85ab25616b6304151452b2b4ff5416194d1b747
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is a PDF containing numerous links to compromised WordPress sites, identified as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://anhuizpyy.com/upload_fck/file/2021-6-20/20210620000630632552.pdf In PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/5cdekrdg5hg7ai09em91u0d115/bajeveninagodeseni.pdfIn PDF document text
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079eda0c9dc5---reditaf.pdfIn PDF document text
    • http://workcoop.org/fckeditor/userimages/file/20210529194347.pdfIn PDF document text
    • http://vishwkarmaenterprises.com/webroot/img/userfiles/files/savut.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/31cf39007808d9bb8862f04cd4e2eb6e/jufikizuxalawavamojobeda.pdfIn PDF document text
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/1ebc3ed18a01f435608fca83ef7bb9a5/xogobudokinasasa.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/avibm63a54h4lfdcnq6pscmo3u/75245197967.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d5434c122c---90047738889.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/saxoxibegimon.pdfIn PDF document text
    • http://palakkadtourism.in/ckfinder/userfiles/files/gomazaluwivuzegofujexuzu.pdfIn PDF document text
    • http://aep-tc.com/cache/fck_files/file/75255725903.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160a8ef7a8de26---56601444205.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a948cddf5ae---19252244893.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2cc1422861---zigat.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/nohf7jnjliklpp6ht95shsne61/32824007135.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=cursive+font+cssPDF link annotation
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f67c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF67C 4600 bytes
SHA-256: 6aaa0a446605757b6ebb8f6a86a02c3d944bd57e654169ebad6da8aadf07a6b4
font_01_sfnt_off0001063a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1063A 11792 bytes
SHA-256: c623541457151586af28ea638464db209042727d32543c667969c2c175f4d675