Malicious PDF — malware analysis report

Static analysis result for SHA-256 88d31602144417c1…

MALICIOUS

PDF

87.1 KB Created: 2021-08-09 23:49:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: cf8f79cad8085311e0ab9442626bbe50 SHA-1: 376b8ee3a8fb12236a1f72b4fcab4ed8a933dae1 SHA-256: 88d31602144417c14e9564e5e7476a67e75f5217f6c7e29fdde5cba961fd3145
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external links, many pointing to compromised websites or disposable hosting. These links are likely intended to trick users into downloading malware or visiting phishing sites, as indicated by the 'link farm' and 'phishing' heuristics. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://queure.ru/uplcv?utm_term=download+watch+dogs+for+android+free PDF link annotation
    • http://nhuaduongnhapkhauaz.info/upload/files/dubimesagatuti.pdfIn PDF document text
    • http://rgjbreunion.com/clients/6/69/6950e03db8b1ea894755b369f0a03c31/File/namejatobaren.pdfIn PDF document text
    • http://steps4cancer.org/clients/a/a7/a78c374070a178914b502abaf3db82b8/File/62608461358.pdfIn PDF document text
    • https://mls.lighting/wp-content/plugins/super-forms/uploads/php/files/b0ad7ab544b4f9da5f4a0c1eb5bfe464/lipuzanivasije.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16081c12d96c01---jofagogeruwogifabi.pdfIn PDF document text
    • https://almuhja.net/ckfinder/userfiles/files/53526730048.pdfIn PDF document text
    • https://jdlpartnerss.com/userfiles/file/kilafo.pdfIn PDF document text
    • http://alexhofford.com/temp/files/file/mugigalunu.pdfIn PDF document text
    • http://xn--o79av69abka850ab6c.com/upload/file/202108082028531096.pdfIn PDF document text
    • https://phr4u.com/files/virapaj.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b5761348ef9---53326452018.pdfIn PDF document text
    • http://cosmic-kino.ru/sadm_files/73909534453.pdfIn PDF document text
    • https://khonggiansachhanoi.vn/uploads/files/vukavaduruzafoxo.pdfIn PDF document text
    • http://fygl.net/uploads/file/201750194537.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160903cb104857---89423724534.pdfIn PDF document text
    • http://sakem.org/userfiles/files/66897582244.pdfIn PDF document text
    • https://cyberbirddog.com/userfiles/files/31880728143.pdfIn PDF document text
    • http://creativeindustries.ru/uploads/userfiles/file/14648182858.pdfIn PDF document text
    • http://hotelbelleepoque.bg/userfiles/file/xegow.pdfIn PDF document text
    • http://carnow.jp/js/upload/files/39926574043.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c86980baf62---sobifarixemoxivituwuzuxi.pdfIn PDF document text
    • http://to-tuong.com/media/ckfinder/files/fifitulozakefo.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1608688593b596---rajonabirukirur.pdfIn PDF document text
    • http://indianspringhomes.net/userfiles/files/nufogasamemeferer.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_off0000f0e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E1 10844 bytes
SHA-256: 2ef6ba1fd95d5fd19cf8cb4f93bc587203375c4681a5744475091eb54a609e2e
font_01_sfnt_off000109ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109AE 17608 bytes
SHA-256: 8f5b750504b048401fedb539c9e09d586f076a93a1df5a302af68a48fda86412
font_02_sfnt_off000136be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1