Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c42a071699af99d…

MALICIOUS

PDF

75.5 KB Created: 2021-06-09 01:29:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 646964e3e83cdd4baacc2194dd2431a6 SHA-1: 74a1d006c975efd8477a8395ae243726d33197b9 SHA-256: 0c42a071699af99dd4e23f715e09b11ba1cd46c58630a90a558a3449db97daff
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external links, many hosted on compromised CMS upload directories, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, appears to be related to 'chess puzzles with solutions pdf', a common lure for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://wastran.ru/uplcv?utm_term=chess+puzzles+with+solutions+pdf PDF link annotation
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160879b5111534---8054376080.pdfIn PDF document text
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/mb7m3elbfl92qeb2jqlenutal1/vitemuxejezariwu.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/160946b247c9cc---solufamopiradokupi.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/3d5101552056bcacfbf271ce5db0e018/fomopisukodozo.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160906d595a0f8---13570010302.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160949c38777d3---bixisuboxasub.pdfIn PDF document text
    • http://webursitet.org/Files/file/korisijedirevela.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/091253346723.pdfIn PDF document text
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/160abe6a248c4e---56626152824.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/d4f09e7e65ffa83b522666ea8ab4823e/54319535468.pdfIn PDF document text
    • http://cz-synergy.cz/data/file/buvidevamesetip.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9d63188ec---tutegitadujokibe.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/16070e71107951---renajapulirabapim.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a59c9d25d39---guxesodaxajavogogaw.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/salofonarapuke.pdfIn PDF document text
    • http://auxerretv.com/content/public/file/2654701049.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eddf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDDF 4868 bytes
SHA-256: f18129aaf94c19fca31980193a71973137fb5e9135a6c84828e35b0f081c077f
font_01_sfnt_off0000fe89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE89 10184 bytes
SHA-256: 9195eb7cc4f29be8e2163b13c8fc6a70d8194fa2d765be0f919a478a6452a4a0