Malicious PDF — malware analysis report

Static analysis result for SHA-256 3dd23d2154291df6…

MALICIOUS

PDF

71.3 KB Created: 2021-09-06 11:07:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 73b742bf1ec3930686e272069d62dd26 SHA-1: 3c32fe9c7c48ac80b885352341c380890aba4771 SHA-256: 3dd23d2154291df69bead74091bfad8117e093ceb1df584437ec997dd14f99b4
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to other PDF files hosted on various domains. Heuristics indicate this is a link farm, potentially for SEO manipulation or to distribute further malicious content. The ML classifier strongly flagged this PDF as malicious, and the presence of external URIs suggests an attempt to redirect the user to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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=civil+rights+act+1955+pdf PDF link annotation
    • http://htcable.cn/d/files/64164272188.pdfIn PDF document text
    • http://dymenahealthcare.com//upload/fckeditor/file/23265806847.pdfIn PDF document text
    • https://aventura-agence.lu/userfiles/files/41757157465.pdfIn PDF document text
    • http://bukharageorgia.com/sites/default/files/file/lopukatepev.pdfIn PDF document text
    • http://polesprogettazioni.com/userfiles/files/10631358778.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/26431712956.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/8b9afaaf4ee730cf85ab1c6c553caeb6/3286494512.pdfIn PDF document text
    • http://dotacjedlaoze.pl/userfiles/file/44756293561.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/pf71g5vrlb5js60g4cpkno7l00/segemitadovemikujamedida.pdfIn PDF document text
    • http://ebrinteractive.com/userfiles/file/71993820327.pdfIn PDF document text
    • http://keitbg.com/images/files/85334806338.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/1610c081019ad3---wubiko.pdfIn PDF document text
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607152140f343---lolef.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/23935017881.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/mokexutobux.pdfIn PDF document text
    • http://thallo-food.hu/uploads/ckfinder/userfiles/files/88773066637.pdfIn PDF document text
    • http://bjsprt.com/uploadfile/file///2021052205465189.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/dafuxakemamokesifobalotow.pdfIn PDF document text
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070be471d1c4---73346970484.pdfIn PDF document text
    • https://pediatricpotentialsnj.com/PP/PPpng/files/razulafemobikarotik.pdfIn PDF document text
    • http://architects-desk.com/uploadsfile/netotosedepijutemigib.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_off0000b35e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB35E 16664 bytes
SHA-256: e069c70492b1a21737d06ebbfc6c2b86b5d54abf098f4b30979b8515247c189f
font_01_sfnt_off0000de7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE7D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f694.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF694 10992 bytes
SHA-256: 4e632756671bf9804854852b3501c59ba162d7afd0053bbdb65c7b9d6f28f9e5