Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9903577c17f1c39…

MALICIOUS

PDF

78.5 KB Created: 2021-06-08 23:36:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 28f3419147b85c2fd777b723b17d4547 SHA-1: a8f058fe8371f8c2503849f5de2d6dda63c055f9 SHA-256: f9903577c17f1c39e7f0161fc8ea223b3e13b9b5223d55c88565a465e7336f6a
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document contains a link farm pointing to compromised WordPress sites, likely serving as a lure to download unwanted software, as suggested by the 'nfs world offline server download' UTM term. While no scripts were explicitly extracted, the presence of numerous URLs on compromised domains suggests an attempt to distribute malware or phishing content.

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://pistant.ru/uplcv?utm_term=nfs+world+offline+server+download PDF link annotation
    • https://www.kalirich.com/wp-content/plugins/super-forms/uploads/php/files/j0giq1js58gdq8ir50ofbop976/21260851354.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d1d55e9e70---2689060648.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/5e58ce8c212d7422e761ff98f9943b0e/91461739936.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/1agdkri2rrsm0b27u63vlorm6h/3688093135.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/7e20469af510eb62dd9f4479ddb56b66/16175225947.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/82019709496.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/6f234bb3d4fdb3d3331ce59faddd7d66/kixanipoxotefesatef.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aba8bde945e---51570782160.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16078e4da6f701---datokedasemaj.pdfIn PDF document text
    • http://servmed.net/userfiles/file/sopivuzur.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/5ajta62fmir70635r1srcrbgp2/titatomutasalaji.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076b638d2a57---pilewinugibonagav.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/ls01c0j9k4e7hceg17lf6d0d45/fitenukemenonolegurafoxed.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adcc985402e---71266019933.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/5165iu2f2mvh331aoubnn07qj1/vezedut.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_off0000e866.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE866 5024 bytes
SHA-256: f525a803d4636583363237fae2676b620ab87bfbfd17bce78b4a9b1e4769f878
font_01_sfnt_off0000f9aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9AA 15960 bytes
SHA-256: 2a50663d180c5aaaa92a7fff0138df329546894c29b017c2babd0f365a439c29