Malicious PDF — malware analysis report

Static analysis result for SHA-256 9d73b88c4e7c0ff7…

MALICIOUS

PDF

70.0 KB Created: 2021-10-02 22:22:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 370e1061090481cf2e1111dbd1a1c5bd SHA-1: 6b39f6347890d107bec2a93c02331bf98fad0e14 SHA-256: 9d73b88c4e7c0ff72af155dc8f393a2dbaa4ca588c50f339f2e3884ef658a2d8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains a link farm pointing to multiple compromised WordPress upload directories and other disposable hosting sites, suggesting an attempt to distribute malicious content or conduct phishing. The presence of external URIs and the nature of the heuristics indicate a likely intent to redirect the user to malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161580fe97307a---taguderorinajoxume.pdf In PDF document text
    • http://hichipper.com/hichipper/uploadfile/file/2021090307353173499.pdfIn PDF document text
    • http://smartwealthhk.com/userfiles/ximamumadogedemusumexose.pdfIn PDF document text
    • http://adasbruiloften.nl/userfiles/file/13594614609.pdfIn PDF document text
    • https://www.casestilistas.es/ckfinder/userfiles/files/1820736514.pdfIn PDF document text
    • http://centonze-vini.com/userfiles/files/bodobusafukagejezojek.pdfIn PDF document text
    • http://carrollcountylawyers.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/69068906099.pdfIn PDF document text
    • http://mnwebdesign.dk/userfiles/file/74810596931.pdfIn PDF document text
    • http://madurastones.com/userfiles/file/73550593173.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613ce2b46f44f---tizunuvoxarus.pdfIn PDF document text
    • http://juentai.com/userfiles/files/kajawovagotiwosimupaxop.pdfIn PDF document text
    • https://carolinevlieghe.fr/images/file/33633096649.pdfIn PDF document text
    • http://newtrichur.com/userfiles/file/xawunuxadigaw.pdfIn PDF document text
    • http://hbtsap.com/Upfiles/news/file///53616355695.pdfIn PDF document text
    • https://baruipur.org/ckfinder/userfiles/files/9314562380.pdfIn PDF document text
    • https://bbu.vn/Images_upload/files/33807309219.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/30791452494.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/vaxonisaxi.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131b86d48deb---71688998498.pdfIn PDF document text
    • https://bankubezpieczen.pl/userfiles/file/gexosuradepasu.pdfIn PDF document text
    • http://antonioruizabogados.es/userfiles/file/26783636069.pdfIn PDF document text
    • http://cck-brno.cz/ckfinder/userfiles/files/68783687352.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=harry+and+the+dinosaurs+go+to+school+pdfPDF link annotation
    • 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_off0000aeb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEB2 11104 bytes
SHA-256: ff97118c6c295498efdc8a12d82d95624a43572c67b9e6a73088fae568b0bbab
font_01_sfnt_off0000c843.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC843 16628 bytes
SHA-256: 2f09ce5af055c5359f8cd0652163e21a793183b10660c29a95160315ea3e3c28
font_02_sfnt_off0000f26f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF26F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1