Malicious PDF — malware analysis report

Static analysis result for SHA-256 87d3406e43b6458d…

MALICIOUS

PDF

83.1 KB Created: 2021-09-12 17:27:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 5317144a6cd221da4480595b3f321c98 SHA-1: a92422e2c3e515b41b2f8c62e19f33995d063824 SHA-256: 87d3406e43b6458db1dd8b0293523fe04e453c847aa2600aac8bbb80d12b28f7
126 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 contains numerous embedded URLs, many of which point to disposable domains and are structured as link farms, suggesting a phishing or malware distribution campaign. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is designed to host many links on potentially untrusted sites. No scripts were extracted, but the presence of many external URIs is a strong indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://chcial.ru/uplcv?utm_term=oxford+advanced+learner%27s+dictionary+10th+edition+apk+crack PDF link annotation
    • https://kligi.viart.lt/ckfinder/userfiles/files/81854703253.pdfIn PDF document text
    • http://1000projects.ru/upload_picture/file/25674579715.pdfIn PDF document text
    • http://konberdbio.com/upload/files/18998417886.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1631411808.pdfIn PDF document text
    • http://thangmayedex.com/webroot/img/files/zifokokufa.pdfIn PDF document text
    • http://www.pics4us.de/userfiles/file/xajavikoketaxixiwubur.pdfIn PDF document text
    • http://gorod-r.com/userfiles/file/newiwojunovifa.pdfIn PDF document text
    • http://matras-devison.ru/upload/file/pubizosuvolaribonifusolo.pdfIn PDF document text
    • http://sandlnae.com/data/editor/file/bidifam.pdfIn PDF document text
    • http://xedaptap.net/userfiles/file/59204280903.pdfIn PDF document text
    • http://stauarchitetti.eu/userfiles/files/12243567531.pdfIn PDF document text
    • http://quaisetoiles.fr/img_pages/file/xanigilegek.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2867ade4b---nigonuvaz.pdfIn PDF document text
    • https://www.jakketoes.be/ckfinder/userfiles/files/kesivexamosejavu.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/daxoxileru.pdfIn PDF document text
    • http://linuxnewyork.com/draft/media/zusulitevivurubakivoxon.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bac4fbc698---rijunimatudarofema.pdfIn PDF document text
    • https://alaskaproauto.net/nbloom/fckuploads/file/12588517659.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/gibuzugonogutitizokuwo.pdfIn PDF document text
    • http://apisicul.com/userfiles/files/lugerakepudonoxelikaser.pdfIn PDF document text
    • https://fonixkoncert.hu/upload/file/31521890068.pdfIn PDF document text
    • http://kozszemle.hu/uploads/files/larasarisoxemojuj.pdfIn PDF document text
    • http://dungculamdep.com/fckeditor_userfiles/file/33892704316.pdfIn PDF document text
    • http://stefani.cz/fck/file/fagomuv.pdfIn PDF document text
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/69109491511.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_off0000d7ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000efe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE0 19744 bytes
SHA-256: ebd4d7d1dab4c97a6a3d1cac46fe67dd45b33b0575860c3b0604a6eb22b7eb5f
font_02_sfnt_off00012389.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12389 11324 bytes
SHA-256: 6e504fdac7245978a94d481fd5c7b34e96e424e5a7f7436d7b823940ecb3b1df