Malicious PDF — malware analysis report

Static analysis result for SHA-256 391fdbff2d5ce2af…

MALICIOUS

PDF

81.5 KB Created: 2021-06-13 17:17:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 290edca79b5e5d4bf6e2a1030da553ac SHA-1: 51ed6bf83a3cdc9b372a16104879c47841026c4b SHA-256: 391fdbff2d5ce2af5c9e203b354c131233e94467de58e2ab8f1153fde8891047
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to compromised WordPress sites, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://smidgel.ru/uplcv?utm_term=best+file+format+for+cv PDF link annotation
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/cca7fb3204ad8a1a71530f6da3a90559/36801526348.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/91889492526.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609a96f78a2da---73319644853.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202105181608491534.pdfIn PDF document text
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/876210d012b82455b4330a39cde78547/29457509742.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608115681796f---xidobiraf.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/98d75c5e77cc87fa756765db69af6590/92898101051.pdfIn PDF document text
    • http://jjmcp.jp/userfiles/Image/file/japufazirevipedadakir.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160aa603e43428---48265387103.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/wifomijosedawanilopipiraz.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca955e3f93---8348153713.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/761a3e65730ec6cf3a97a3016b69117f/kipuwinosid.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a3c1ce2ab7a---85188374129.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/dufafogi.pdfIn PDF document text
    • https://luxmarketing.agency/wp-content/plugins/super-forms/uploads/php/files/kekioa0kbhlo8gb29h708q0dis/20037000159.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/tofunedoziguwiv.pdfIn PDF document text
    • http://elcampoeco.org/FCKeditor/file/giwevaviniwizapis.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_off00010217.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10217 5136 bytes
SHA-256: 765d9a0c2cf7f694b13981ab6f4b25cdd67ccc38d7f3d6d6e1ec023a9171f72b
font_01_sfnt_off00011381.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11381 10584 bytes
SHA-256: a523ad23fb2a1dfbc2870a22e23bb53ba9095625b21057bd8c4b3d3ad6a49c7e