Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdcb684c31f7c9ee…

MALICIOUS

PDF

81.8 KB Created: 2021-09-21 05:24:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a211146b0e5c8b9bd4e2709d33b16049 SHA-1: 6b0a240fb80b68d248496051e6cc1f7bb4099760 SHA-256: cdcb684c31f7c9ee913d809768f76af7f53493de58e617081f99034b31509c83
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to disposable domains, indicating a link farm or phishing lure. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://archism.ru/uplcv?utm_term=how+to+turn+on+internal+audio+recording+on+android PDF link annotation
    • http://rowadhr.com/app/webroot/upload/files/86517815347.pdfIn PDF document text
    • https://oasis-travel.ro/files/94636831042.pdfIn PDF document text
    • http://zangerlelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kidexokijerup.pdfIn PDF document text
    • http://caogenzhiben.com/filespath/files/20210902122643.pdfIn PDF document text
    • http://net-marketing.hu/images/files/81989197484.pdfIn PDF document text
    • https://xeroxexpres.cz/userfiles/file/wefazu.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210914072812778.pdfIn PDF document text
    • https://momentous-inst.com/uploads/image/files/jisokagejesipoposejika.pdfIn PDF document text
    • http://imapbook.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/zejivujabalanazi.pdfIn PDF document text
    • http://cameralehiep.com/hinhanh_fckeditor/file/86676424982.pdfIn PDF document text
    • http://bakineshr.az/ckfinder/userfiles/files/lawesakinis.pdfIn PDF document text
    • https://laptoptranganh.com/data/dulieu/files/36170696984.pdfIn PDF document text
    • https://bjjewels.net/nbloom/fckuploads/file/kelemukoke.pdfIn PDF document text
    • http://xn--80aafkatcapceshpicpg3h.xn--p1ai/pict/file/88008746101.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161391ececc1ba---50265845518.pdfIn PDF document text
    • http://thegioichuyendong.info/app/webroot/upload/files/95411732433.pdfIn PDF document text
    • https://togeltop.net/contents/files/17999629733.pdfIn PDF document text
    • http://perfekt-dom.pl/designhome/admin/userfiles/file/81939594756.pdfIn PDF document text
    • http://ambvetsanprospero.eu/userfiles/files/48166280677.pdfIn PDF document text
    • https://associazionemusicaviva.it/uploads/file/45725765635.pdfIn PDF document text
    • http://riversedgefm.com/files/file/mojonewesejoralad.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/sabobotubavemolaken.pdfIn PDF document text
    • http://carraracucinecomponibilitrapani.it/userfiles/files/41881254424.pdfIn PDF document text
    • https://digireg.at/upload/rupoxugav.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/29c6b5b33bbd415410fb48dee8ad7514/zekogekowivaz.pdfIn PDF document text
    • https://nullemont.fr/nullemont/ckfinder/userfiles/files/gusejibaxug.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_off0000dc0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC0F 10556 bytes
SHA-256: 378d9ba6176c1bb59d0ed0984d938d5401ee6bf39153300381b9d305ccdfed6f
font_01_sfnt_off0000f407.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF407 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C19 17516 bytes
SHA-256: 6f06847768f448fee1803686c110377fc71cc235c0c92ed3b2a8d3b39638cbff