Malicious PDF — malware analysis report

Static analysis result for SHA-256 47bff33bdd2f9221…

MALICIOUS

PDF

69.9 KB Created: 2021-09-04 18:33:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: de1f43232bd22b3be713af19af16a30f SHA-1: cd9c44f5bf840cee61e1a41363abfcc088a8fa5b SHA-256: 47bff33bdd2f9221cbd663c45fcaf01d9417b25987a33ff8f385861ab3c0ec38
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external links, many pointing to domains associated with compromised CMS uploads or disposable hosting, indicating a link farm designed to lure users to potentially malicious sites. The ML classifier and ClamAV detection strongly suggest a phishing or malware distribution intent. No scripts were extracted, and the document body was unreadable, but the heuristic findings are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://medvor.ru/uplcv?utm_term=valoracion+preoperatoria+pdf+2018 PDF link annotation
    • http://intelekt.biz/uploads/pages/files/dadupugabevitumixozese.pdfIn PDF document text
    • http://vintageguitar.ru/ckfinder/userfiles/files/watebirukake.pdfIn PDF document text
    • http://gwtcs.org/Content/uploads/files/xaxujukozunotexofatupo.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082ee3d60591---zowuvimibijasarobe.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609f9b25cae74---91241947461.pdfIn PDF document text
    • http://petra-dario.info/upload/datoteke/88047286404.pdfIn PDF document text
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/061172cc9a257ea4b449b3d0cbf6b13d/zurosigedaxokeb.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/fopefelodorokozawon.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b7b60cc299a---tuvojekovuxojobuvunejiju.pdfIn PDF document text
    • http://mayjack.com/upload/files/gumetavobenewadodoxajax.pdfIn PDF document text
    • http://stolizstekla.ru/userfiles/file/zijumobupemeratapusom.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/kalezizozuzepijopaparet.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/86fc249300150da3b0721544f998a726/wusumud.pdfIn PDF document text
    • http://tahi.hu/ckfinder/userfiles/files/puvekepi.pdfIn PDF document text
    • https://rux-thai.com/ckfinder/userfiles/files/jikedusuradezasosola.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/16080e06373cef---7936785845.pdfIn PDF document text
    • http://micronforgacsolo.hu/UserFiles/file/10000689288.pdfIn PDF document text
    • https://mimpishio2.net/contents//files/32963413566.pdfIn PDF document text
    • http://endustriyelkiralama.com/wp-content/plugins/super-forms/uploads/php/files/3keusn2qr0istu3k6irht9fp8v/83918205630.pdfIn PDF document text
    • http://hccc252.ca/clients/e/e4/e484b38507f190a955b66748903449e1/File/7454555476.pdfIn PDF document text
    • http://bocghedanang.com/media/ftp/file/47042649634.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_off0000b0cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0CB 15704 bytes
SHA-256: 77d3c21d679ea48ebbc181fa3c17abb23fcb4be49d28a80ba8037f098a7edc21
font_01_sfnt_off0000d8b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f0cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0CD 10916 bytes
SHA-256: 97f6658c6885a330634677f4a03f1245c4013e8fc8d63c9e9459cbeabab645aa