Malicious PDF — malware analysis report

Static analysis result for SHA-256 2403d7de4886694b…

MALICIOUS

PDF

84.1 KB Created: 2021-09-07 16:35:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5cf8d9e99f7646549b84d32b9c5ca665 SHA-1: 598efa7ef6d0730dc3b4e7b30dbcdb3e622a07ce SHA-256: 2403d7de4886694b86df73a0df612367bb3ab42d67457465320372051911afc6
196 Risk Score

Malware Insights

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

The PDF contains multiple links pointing to compromised CMS uploads and disposable hosting, indicating a link farm designed to obscure the final destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The embedded URLs and link farm structure are indicative of an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 http://klefmarken.se/upload/file/nisimakufo.pdf
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/b22b3cfc40158b0f4e677cb6b3211828/wijijemekawiti.pdf
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/vapugebenopuvapinomonan.pdf
    • http://corkpotters.com/images/26052994918.pdf
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ec4dc12a75b---xoxinemedagopisojomutu.pdf
    • http://chistogood.ru/admin/ckfinder/userfiles/files/tiburekoxidewelome.pdf
    • http://dragonera.cn/admin/userfiles/file/doxebeze.pdf
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd94ab2406---33803189706.pdf
    • http://ambulatorioveterinariobubiniregini.eu/userfiles/files/58277013029.pdf
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/p1bbhsgmlqb85ld2jg3vc7d28p/gafenez.pdf
    • http://jysfh.com/upload_fck/file/2021-8-21/20210821073436266418.pdf
    • https://salubrismd.com/wp-content/plugins/super-forms/uploads/php/files/a899cbc7a43ee1764f2d8713184f5a7b/jasifuluwitajonuwunuduw.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a40d05a9073---jomopobopibidiges.pdf
    • http://hasyo.net/files/file/64966593910.pdf
    • http://vuadiemtayninh.com/hinhanh_fckeditor/file/59542680379.pdf
    • https://spectrumohio.com/wp-content/plugins/super-forms/uploads/php/files/6de9aec28abd65df74f85abfd49f730d/kezetuse.pdf
    • http://unsersohn.ch/images/file/vibalewurawinuvixaxuvako.pdf
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/160e5239b949de---xetemekezoxulipofatojif.pdf
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210906_000626.pdf
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607f7db25eb0d---11663915577.pdf
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/f58124b75387fc3bc64444bd498170a3/87560593730.pdf
    • http://superplasticizer.cn/d/files/misexonakunozulofitemeka.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=pr%C3%A4positionen+deutsch+%C3%BCbungen+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d625.bin
ee57c0311538abb21eddc3ddb503cb63b69fef8d5313978d80aa1080925a6afd
pdf-font-stream PDF embedded font (sfnt) at offset 0xD625 23000 bytes
font_01_sfnt_off00010ec6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10EC6 16792 bytes
font_02_sfnt_off000126dd.bin
96538ea6243e0d7e062aa1ca5a91d42751a1334c044c5d2e095683f637e41a2c
pdf-font-stream PDF embedded font (sfnt) at offset 0x126DD 11380 bytes