Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef436325888e74b7…

MALICIOUS

PDF

77.3 KB Created: 2021-09-20 14:35:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b86788542f51695a0b423f02645efb8a SHA-1: 959b82703e9a9600ba82cbb40597d14b4fe91804 SHA-256: ef436325888e74b7e91870cd2cbe8ceabe7092fb442d109302762c7ea00ed6c3
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier, indicating malicious intent. It contains a link farm with multiple URLs pointing to potentially compromised or disposable hosting, suggesting an attempt to lure users to external sites. Embedded JavaScript was also detected, which could be used to further exploit the user or redirect them.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://khonggiansachhanoi.vn/uploads/files/62712724359.pdf In PDF document text
    • https://chineseclothingonline.com/File/60187684143.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/161321c56381f7---tageberizow.pdfIn PDF document text
    • http://greensketch.in/userfiles/file/91921866458.pdfIn PDF document text
    • http://exito-opakowania.pl/userfiles/file/fafozaxusuxigadagev.pdfIn PDF document text
    • http://castudio.eu/userfiles/files/62483860893.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/sasunexufabozojivene.pdfIn PDF document text
    • https://swalaya.in/userfiles/file/jubawufevizozisi.pdfIn PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/6922888105.pdfIn PDF document text
    • http://vankouwenenmastop.nl/UserFiles/file/renejorozijejijolomo.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/161421dd78b6c5---51790037308.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/68d2bec8b9858d903b7f251a6fc86480/10919093817.pdfIn PDF document text
    • http://freetourscadiz.com/ckfinder/userfiles/files/datenarufixowid.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/h49cq0pg067g95v6ion93bh063/nexiposupaxe.pdfIn PDF document text
    • https://propiedades.net/ckfinder/userfiles/files/nubigofovigokexufujitovi.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/44570875248.pdfIn PDF document text
    • https://www.travelknowhowscotland.co.uk/assets/js/ckfinder/userfiles/files/39214026179.pdfIn PDF document text
    • https://daquin-ferriere.fr/userfiles/file/sobabiraruwubazabisotewap.pdfIn PDF document text
    • https://calson.garment-pro.com/ckfinder/userfiles/files/91613262518.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16131444018f2d---tidax.pdfIn PDF document text
    • http://winfielddeli.com/ckfinder/userfiles/files/vigalulomive.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/vituwozugoponakovom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=mmorpg+no+pay+to+win+androidPDF 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_off0000c85f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC85F 18248 bytes
SHA-256: 8f5e02a81c16b9f9f15052a72a6e155377b948f8ed60d62e45946b7928db4dab
font_01_sfnt_off0000f793.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF793 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010faa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FAA 10580 bytes
SHA-256: 759b709ec8c39ca47fc8b7b8a339e0acc87c49b1133865036e6c1e546129d6c6

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