Malicious PDF — malware analysis report

Static analysis result for SHA-256 a40b43866a54d2d0…

MALICIOUS

PDF

71.0 KB Created: 2021-09-21 02:21:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: caf758b3e831251c893285af78dba8ed SHA-1: d3bd525fe1632bc87a95cb2961d740295b9c2a19 SHA-256: a40b43866a54d2d05b6e9236513f8005f62d61f0e38de494d6cfd12a65ebf096
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs, many of which point to potentially compromised or disposable hosting sites, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://chcial.ru/uplcv?utm_term=11th+std+computer+science+book PDF link annotation
    • https://siroyensao.com/upload/files/dogevu.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/161335f1b22dc4---58692286497.pdfIn PDF document text
    • https://hahapediatric.com/uploads/files/202109060031368787.pdfIn PDF document text
    • https://xn--interpeas-r6a.es/upload/files/4851726955.pdfIn PDF document text
    • https://mehfermobilsaglik.com/userfiles/file/47160770345.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/85058011354.pdfIn PDF document text
    • http://wakabaeducation.com/userfiles/file/lofemunoxogawuko.pdfIn PDF document text
    • http://foreverymuslim.net/home1/forevev3/public_html/foreverymuslim/upload/file/86720681653.pdfIn PDF document text
    • https://trungtamgiasuhcmmq.com/uplaod/quangtri/files/keratonukiz.pdfIn PDF document text
    • http://thetsaban3watnuea.com/UserFiles/file/95133993716.pdfIn PDF document text
    • http://studiodabo.eu/userfiles/files/61064580295.pdfIn PDF document text
    • http://abwingssuffolk2.com/uploads/files/jabusas.pdfIn PDF document text
    • http://naso10.com/userData/board/file/24384602121.pdfIn PDF document text
    • http://sksound.com/userfiles/file/26204581555.pdfIn PDF document text
    • http://casadiriposomarsala.it/userfiles/files/46833684203.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613104343e029---turamela.pdfIn PDF document text
    • http://escritacontabilidade.net/fotos/news/file/vefifixepozadazesafosez.pdfIn PDF document text
    • http://www.siposferenc.hu/html/sozekosupulopuvaloduraxud.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141897f7131e---35449289594.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/jufiredefaw.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146cddc55d28---29336349186.pdfIn PDF document text
    • http://viral-list-monster.com/ckfinder/userfiles/publics/files/peladapavefepegaba.pdfIn PDF document text
    • http://exosushi.com/uploads/files/kitedajazimikubutoxodipi.pdfIn PDF document text
    • https://www.sonorisation-auxerre.fr/ckfinder/userfiles/files/vivoj.pdfIn PDF document text
    • http://moskvaznaet.ru/upload/files/mikikeb.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_off0000b596.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB596 15796 bytes
SHA-256: 6960b12eaf7291184cadff9a151204821cead4d982535ed1d886489b19e2e24f
font_01_sfnt_off0000ddc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDC6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f5dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5DD 10860 bytes
SHA-256: b8bdcbb71202a314f01d0135589b3304f8c41bc7089859273b681a2a16e22b0e

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