Malicious PDF — malware analysis report

Static analysis result for SHA-256 21969f485d23bf2e…

MALICIOUS

PDF

79.7 KB Created: 2021-08-17 20:21:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a72ecfa2e82364da124cce8830428800 SHA-1: 4e71fdacb007638877b222200bac552c7a617b03 SHA-256: 21969f485d23bf2eb09088488bca251528174e29e27a565bb2939f0aa3a0f81c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan distribution attempt. It contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://catamma.ru/uplcv?utm_term=mainstays+5+shelf+bookcase+assembly+instructions+pdf PDF link annotation
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b56fea51b36---65950287003.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/kuregefezawatunexekul.pdfIn PDF document text
    • http://it-hair.com/userfiles/seligeguwitebobatewo.pdfIn PDF document text
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606edae56f690---foguvobasuzokuvuner.pdfIn PDF document text
    • http://ikkosushi.com/uploads/files/77086895821.pdfIn PDF document text
    • http://ogbchurch.com/clients/880797/File/xonazod.pdfIn PDF document text
    • https://roweryelectra.pl/app/webroot/uploads/file/16258827988125.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/af6143bace8a6dec49b6046650f76801/93561518547.pdfIn PDF document text
    • https://silverstonedevelopments.com/ckfinder/userfiles/files/51622467145.pdfIn PDF document text
    • http://skrutit-probeg.ru/upload_picture/file/13510332923.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/ceek2udq19tg8fuj8cci31h8r7/40730251728.pdfIn PDF document text
    • http://csaladiegyteruautok.hu/userfiles/files/44117799328.pdfIn PDF document text
    • http://tiwtactic.com/userfiles/files/jaxazewarumemasapijive.pdfIn PDF document text
    • https://monyetjoget.com/contents//files/22659231545.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/fqs4fc7h44esnkn7lpdnbs9ksl/javanozer.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1dd55d6b3e---dakuwowawodumepudo.pdfIn PDF document text
    • https://kogan-photo.ru/wp-content/plugins/super-forms/uploads/php/files/34ccc7fa6d7c8f5069eab8216881a736/jalinamutotona.pdfIn PDF document text
    • https://schmitz.cz/res/file/58485838310.pdfIn PDF document text
    • http://hondatayho.vn/images/ckeditor/files/xumekelijegopenunediseg.pdfIn PDF document text
    • http://closehorses.com/userfiles/file/26844805150.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ecfb12df7f1---gujiwilomokesana.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_off0000d075.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD075 17284 bytes
SHA-256: 9d84fa8171df5f1be07e5b4c52173283588cfc0e0cbde969bdd1006efeb1d2bf
font_01_sfnt_off0000fd7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD7D 11456 bytes
SHA-256: 4f051a3428a976ff22edb48184d1b7d08f2d0ed8a84ef29bf7958e08dad2cf0c
font_02_sfnt_off00011837.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11837 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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