Malicious PDF — malware analysis report

Static analysis result for SHA-256 a40ec57aeb6a3e66…

MALICIOUS

PDF

74.3 KB Created: 2021-09-06 17:23:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fdd4e7e563b30b1b63d78ec13b46fc10 SHA-1: 3013ec59d800b30ee7140980c4e1a002b478fb58 SHA-256: a40ec57aeb6a3e66c3b6685506da58d7b7c3fb8cfaf4d477b57ec371f4ffd87d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised or disposable hosting. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and URL analysis strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://stef-nancy.fr/upload/document/43100068237.pdf In PDF document text
    • https://biocenfis.es/uploads/assets/file/wuvudilozumekaso.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608421e29753f---69060149549.pdfIn PDF document text
    • http://delshadian.com/public/userfiles/file/jinezibodafetobur.pdfIn PDF document text
    • https://www.hkha.com.hk/ckfinder/userfiles/files/kixofojugozas.pdfIn PDF document text
    • https://thinkhigh-tech.com/d/files/6553519006.pdfIn PDF document text
    • http://hosteleriayvending.com/ckfinder/userfiles/files/92969936315.pdfIn PDF document text
    • http://abwingssuffolk1.com/uploads/files/76026859779.pdfIn PDF document text
    • http://bobmeetin.com/media/galleries/files/luvedapagede.pdfIn PDF document text
    • http://angelascanu.it/uploads/file/55593809313.pdfIn PDF document text
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/f7010465982c5f58938e298b8e466f7f/zesigakavamejojozij.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160899d440b65b---goxezimexezaxozakidube.pdfIn PDF document text
    • http://alliance-ic.ru/uploads/file/49921705629.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cb33941d65---25457675450.pdfIn PDF document text
    • https://aplusadvance.com/naver_editor/data/file/31388167785.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ff440ebe6f---46525666631.pdfIn PDF document text
    • http://aktifbant.com/resimler/files/rizagufapese.pdfIn PDF document text
    • http://vds-construct.pl/userfiles/file/75999172280.pdfIn PDF document text
    • http://champagne-marc-chauvet.com/images/files/xosevapufelogufo.pdfIn PDF document text
    • http://chiangmai-clean.com/user_img/files/83393981301.pdfIn PDF document text
    • https://ewastexperts.com/userfiles/files/80280515475.pdfIn PDF document text
    • http://georgewongdesign.com/gwd/upload/files/85874141143.pdfIn PDF document text
    • http://teleinwestor.com/userfiles/file/75931637929.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=destroying+avalon+full+book+pdfPDF link annotation
    • 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_off0000be12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE12 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d629.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD629 11184 bytes
SHA-256: be85bc9e8de80fbb4a0aadc92936a25869cd11733c7bff79236414893aba1770
font_02_sfnt_off0000f017.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF017 16980 bytes
SHA-256: 4d5344133fdaa3af1f42da2b4f4c1759d487aca3b27e1d708286ac4c937afbff