Malicious PDF — malware analysis report

Static analysis result for SHA-256 acf53f35ece5f9f7…

MALICIOUS

PDF

69.8 KB Created: 2021-09-11 19:46:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2f0669ea5f1223e819bb06d40f9df29a SHA-1: 8d799ba130b98cd39ec226cc393d7d090a0d9bcf SHA-256: acf53f35ece5f9f71ba959e409938c6db62658632ef633240c746d0192218d8a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm, potentially for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a common attack pattern of luring users to compromised or malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://nomylo.ru/uplcv?utm_term=adblock+chrome+addon+android PDF link annotation
    • https://www.newhorizonscrisiscenter.org/ckfinder/userfiles/files/73751382634.pdfIn PDF document text
    • http://rucodelniza.ru/userfiles/file/39142115067.pdfIn PDF document text
    • https://trungtamgiasuhcmmq.com/uplaod/quangtri/files/81483355010.pdfIn PDF document text
    • http://winecellarkeeper.com/ckfinder/userfiles/files/tuniva.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/1d0448a4d1ff1d38206d6fd71b6d6dec/41482270094.pdfIn PDF document text
    • https://www.prieur-equipement.com/ckfinder/userfiles/files/sukenesisira.pdfIn PDF document text
    • http://www.adarshvidhyasankul.org/userfilesfile/30840184416.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6f3d18868---funuru.pdfIn PDF document text
    • http://ty-universe.com/image/files/20210910_201145.pdfIn PDF document text
    • http://pp-aqua.com/userfiles/files/vugized.pdfIn PDF document text
    • https://partroyfuneralhome.com/partroy/assets/file/gomupevovudusufapotifap.pdfIn PDF document text
    • http://ckattorneys.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mesimujewixarovaledodezer.pdfIn PDF document text
    • http://shortguycentral.com/ck_uploads/files/28568380513.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16133ade1e0989---8752343790.pdfIn PDF document text
    • http://bzws.zhanyougame.com/ckfinder/userfiles/files/gigox.pdfIn PDF document text
    • http://kaies.net/upfiles/2109051900280051821xw840.pdfIn PDF document text
    • https://marsanz.pl/uploads/fck/file/93754800230.pdfIn PDF document text
    • http://stjconsulting.it/userfiles/files/36040044462.pdfIn PDF document text
    • https://forssh.com/userfiles/file/mibojo.pdfIn PDF document text
    • https://evergreencans.com/userfiles/file/saboriwowogufezopelufamu.pdfIn PDF document text
    • https://le27.fr/docs/file/68400606395.pdfIn PDF document text
    • http://teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/67476285382.pdfIn PDF document text
    • http://urbanelect.com/userfiles/file/nifobogexit.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_off0000af12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF12 17468 bytes
SHA-256: dd0bafffe0a72573650b934369c2d41093dc24e90381c51c0bc6facd0c7e9c8d
font_01_sfnt_off0000d9ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f1c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1C3 10584 bytes
SHA-256: 3b31ebf6c84def71e87107120cf57c31f01dceb41f665af96721716a3ca250b1