Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef23475741334f5f…

MALICIOUS

PDF

71.2 KB Created: 2021-09-20 18:32:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8b2deb067803e0926345fed33a42d715 SHA-1: eea81dc618e6acbe653787d9b3732230b3330ab2 SHA-256: ef23475741334f5f4e5820a86b0b4ef27c63956eebf163612487e60361e090bf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicative of a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://garglob.ru/uplcv?utm_term=friv+net+games PDF link annotation
    • http://preprod.app-nomads.com/ugecam/admin/ckfinder/userfiles/files/nutexomog.pdfIn PDF document text
    • http://canadianrockies.ca/files/file/vorebupinofexikor.pdfIn PDF document text
    • http://flapboxes.custompackageboxes.com/userfiles/files/34502058736.pdfIn PDF document text
    • https://begili.com/uploads/image/files/gozimiwu.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613758365147f---gomitamonupabivugukex.pdfIn PDF document text
    • http://t-eamplus.de/web/editor/files/pazefewimopix.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613e1add9f9f0---povitapexikux.pdfIn PDF document text
    • http://yogaschoolofkerala.com/photos/editor/files/61438434897.pdfIn PDF document text
    • https://guptajimarriagebureau.com/userfiles/file/fosisozusu.pdfIn PDF document text
    • http://klimagra.pl/images/wysiwyg_img/file/98085455054.pdfIn PDF document text
    • http://www.fashiongale.ro/userfiles/files/58795472162.pdfIn PDF document text
    • http://herve-coiffure.ci/files/labatowadabawixefe.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419ae50c8f6---31401713726.pdfIn PDF document text
    • http://zamgph.com/uploads/file/021145448708.pdfIn PDF document text
    • http://pumarecovery.com/userfiles/files/13836026499.pdfIn PDF document text
    • https://next-engineering.com/userfiles/files/xusiretosanomepobapi.pdfIn PDF document text
    • https://databaze-zdarma.cz/userfiles/files/tugazakegivulagazefevibok.pdfIn PDF document text
    • https://gancza-yacht.pl/userfiles/file/gimom.pdfIn PDF document text
    • http://smartdeal.pl/files/upload/files/ginepoturirovuwi.pdfIn PDF document text
    • http://centrlita.ru/archive/image/file/87698480612.pdfIn PDF document text
    • http://change4best.ru/upload/file/35497707007.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/161412ad2ce2a4---bibolokutolame.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_off0000b600.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB600 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE17 10328 bytes
SHA-256: a0018e0fab8b4997f390a9a93bb4580876db97d3f22e725a6423ec0ce33ee830
font_02_sfnt_off0000e55c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE55C 16584 bytes
SHA-256: b4f3017c88d197c6dcfc235be9c3017678d600047a1129886fc6a556e83fc718