Malicious PDF — malware analysis report

Static analysis result for SHA-256 a12dd1c724b5cd06…

MALICIOUS

PDF

74.2 KB Created: 2021-06-04 18:46:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 502a96658c2e055db9e52b0c26113363 SHA-1: a1d4b1d9b56e9593b1ca31292b39358fa6c3af21 SHA-256: a12dd1c724b5cd0650d9770a7274bd651a9f4b5c8823f98da00ec8c8c1609e75
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs and heuristics indicate it functions as a link farm, with several pointing to compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body, though heavily obfuscated, contains metadata related to PDF generation and a differential equation example, which may serve as a lure.

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://huntic.ru/uplcv?utm_term=second+order+inhomogeneous+differential+equation+example PDF link annotation
    • https://geneticapanama.com/userfiles/file/tepelagozewa.pdfIn PDF document text
    • http://refta-bg.com/userfiles/file/66529321101.pdfIn PDF document text
    • http://alexanderkanevskyartistbiography.com/clientMedia/file/legof.pdfIn PDF document text
    • http://abacusnancy.com/userfiles/file/78685783949.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/e96834eee4df7aeeba741db305192088/gejuredexupuvilex.pdfIn PDF document text
    • http://ya-ke.cn/admin/upload/fibugajifowamepokomikisad.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a55981a97b4---narapadofefobunevewet.pdfIn PDF document text
    • http://rowanfamilyreunion.com/clients/28915/File/milonagovivexites.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1609a560bd4fc0---vidurubikalafozeroputol.pdfIn PDF document text
    • http://woodwork.pl/ubezpiecz/obrazy/file/33301433316.pdfIn PDF document text
    • http://www.molinoag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e896c90c70---88315821669.pdfIn PDF document text
    • https://wecareu.net/ckfinder/userfiles/files/dapakuxazif.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/pozokosubomiteko.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/89u8hn0d7fpubkdd6uvvh1cqsg/wejexurovenuxorirabuwule.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/4cb4a0a887363f7377e683e42e87e790/belomibe.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160866cbc22bcc---ziviwewetisozemefij.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093cf6882f82---33440573379.pdfIn PDF document text
    • https://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/42c935c3f867ae5eff38061d56268fd5/xijikukegovifitaw.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_off0000e0d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D1 5864 bytes
SHA-256: f222bc379cadcec56f3836b6d7885ce5dc542ed4c9e0685e709726057f9648d7
font_01_sfnt_off0000f4a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A3 11288 bytes
SHA-256: 0e25fd265dac63970f06d1c7efd35b1f0993b5f710b736d0ebe298b33dcc7d05