Malicious PDF — malware analysis report

Static analysis result for SHA-256 51d37be145c38b96…

MALICIOUS

PDF

69.1 KB Created: 2021-09-26 04:54:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 76d6b09a592f1d8f53bc9892b887c02e SHA-1: e036451bcde4e8ce89607a037b2d0221946a9c53 SHA-256: 51d37be145c38b961f566257f64e0f6c992d531af435b92ccb3286bd3aa08013
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF that contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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=halo+beyonce+violin+sheet+music PDF link annotation
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16144583510be1---43204351773.pdfIn PDF document text
    • http://wixoon.hu/upload/file/68091495592.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/19731014626.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614d001e17589---77790553281.pdfIn PDF document text
    • http://avanti.pl/userfiles/file/77440891817.pdfIn PDF document text
    • https://fasleh.net/Files/files/vatelikitavuxobuz.pdfIn PDF document text
    • http://cuacongtudongbinhduong.com/upload/files/xedapotan.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/16140828bcbf5e---roluzulimeveduro.pdfIn PDF document text
    • https://leo.tw/upload/ckeditor/files/96876970753.pdfIn PDF document text
    • https://enkaotomatikkapi.com/depo/sayfaresim/file/fijadadagezalasutemunoj.pdfIn PDF document text
    • http://nrgmedia.hu/files/file/91998241177.pdfIn PDF document text
    • http://ahknchem.com/upload/files/69937487486.pdfIn PDF document text
    • https://muzpony.de/obrazki/file/votegibanawoninusi.pdfIn PDF document text
    • http://detskaoptika.cz/ckfinder/userfiles/files/90307546160.pdfIn PDF document text
    • http://madonnina.info/userfiles/files/66613877998.pdfIn PDF document text
    • http://nandishoverseas.com/UserFiles/File/93566413524.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d281fd6b0e---nefiped.pdfIn PDF document text
    • http://www.teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/lezudobogobesi.pdfIn PDF document text
    • https://poker-fire.de/file/kamovadogalukaki.pdfIn PDF document text
    • http://carrasvilla.es/uploads/files/37478142831.pdfIn PDF document text
    • http://telek-trans.hu/editor_up/60403023125.pdfIn PDF document text
    • http://chronocertif.com/userfiles/file/31891805257.pdfIn PDF document text
    • http://bankerz.in/qpic/files/dejekukogipiwugunipesit.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_off0000b119.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB119 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c92b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC92B 14764 bytes
SHA-256: f2131406c3470b1195cbe4824bcf56718933f5063e571dec967f886d4ad7b5f7
font_02_sfnt_off0000edfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFD 10808 bytes
SHA-256: 672de4a8c7e10ab09146bd50ca0b51f7338e7777751aa4355119ecd957cbb3eb