Malicious PDF — malware analysis report

Static analysis result for SHA-256 b322d474631accf3…

MALICIOUS

PDF

87.4 KB Created: 2021-09-12 03:45:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 31a8a836c3cf1333b6a65acf67bc1d8a SHA-1: 81a43ccf41dd74f42634ca0a491256df8274fa2a SHA-256: b322d474631accf38aaf4262ce7d190685a98944568df70d70f1be8418783adc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple external URLs, some of which are hosted on compromised CMS platforms. The presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://philabc.ru/uplcv?utm_term=usmle+step+1+first+aid+book+free+download PDF link annotation
    • http://enovosti.info/ckfinder/userfiles/files/dolobifexoti.pdfIn PDF document text
    • http://canigrup.com/userfiles/file/71604029235.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/96406077188.pdfIn PDF document text
    • https://www.fangjin.org/ckfinder/userfiles/files/2556793017.pdfIn PDF document text
    • http://kientrucphatloc.com/upload/files/1272079092.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/044723a0dfb5527849bc337bddfe6719/fewofosis.pdfIn PDF document text
    • https://noithathoaphat11.com/upload/files/lodubodovotureg.pdfIn PDF document text
    • http://rkmaster.ru/uploads/files/navulegibux.pdfIn PDF document text
    • http://ahdjcm.com/upload/files/pizasubudofozagu.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613680e12d7ea---16428595294.pdfIn PDF document text
    • http://polyalpan.hu/_user/file/64354497137.pdfIn PDF document text
    • http://jerseybankruptcylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mazepupezidibew.pdfIn PDF document text
    • http://jiin-torng.com/uploadfiles/20210903112716.pdfIn PDF document text
    • https://livres-d-art.com/ckfinder/userfiles/files/doxabaxodenifizolijorodu.pdfIn PDF document text
    • https://www.parquesanalbertohurtado.cl/ckfinder/userfiles/files/nofafebe.pdfIn PDF document text
    • http://capableapp.com/uploads/files/bifaxuxulerufazopidak.pdfIn PDF document text
    • http://freeski.hu/freeski/file/saturemujojoru.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161395f6c98bbc---33792172712.pdfIn PDF document text
    • https://savitravel.ro/ckfinder/userfiles/files/zupok.pdfIn PDF document text
    • http://chekeeh.ir/basefile/chekeehir/files/vufugeki.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130171d6f4b3---7115278433.pdfIn PDF document text
    • http://primaria-ciocirlia.ro/media/file/sevajebupevuxalulunerapil.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_off0000ea57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001026e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1026E 11036 bytes
SHA-256: c8178f7a78ebe06f9ca7c46f4fec0b57c1de49a23801e6c81b2d026251b2223b
font_02_sfnt_off00011bef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BEF 19136 bytes
SHA-256: b059072f8124a7ec99566e6e8257dd8d316fa2db5baedd50ca1b6ae550d1697c