Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef6c09043d3c7805…

MALICIOUS

PDF

79.0 KB Created: 2021-09-12 22:59:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2a951d6ec4bb24060dd69cd43a1504df SHA-1: a9ed7ceab1bf94ca82196a7ce00ee49ad6d75b02 SHA-256: ef6c09043d3c78051550616e88fb05572746628b2d4ed622e21641c2727149b0
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM indicates the document is part of a link farm, and multiple unknown URLs were extracted, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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
  • 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 http://erpos.sk/data/files/96945801332.pdf In PDF document text
    • http://sowa-architekci.pl/userfiles/files/9099848240.pdfIn PDF document text
    • http://studioboscono.it/userfiles/files/kewaluzawakutuwezasurano.pdfIn PDF document text
    • http://constantcontinuity.com/membership/data/files/53170806843.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/51fd4d7f2c54a36bdd2a012dc785a907/14344240108.pdfIn PDF document text
    • http://osingenieria.com/images/admin/file/lemalujupebiniteriwujokow.pdfIn PDF document text
    • https://cowik.pl/upload/92846391406.pdfIn PDF document text
    • https://birsamundapark.in/userfiles/files/7373038494.pdfIn PDF document text
    • http://canoto.us/Images_upload/files/kogagumexa.pdfIn PDF document text
    • https://cubic.is/userfiles/file/5206672642.pdfIn PDF document text
    • https://kham.vn/userfiles/file/73335305695.pdfIn PDF document text
    • https://aczv.fr/userfiles/file/jolepadijuw.pdfIn PDF document text
    • http://apisicul.com/userfiles/files/vimakojaxexifuvo.pdfIn PDF document text
    • https://nacituran.com/userfiles/file/24055279852.pdfIn PDF document text
    • https://thokhoavietnam.com/upload/files/sexefepilogewudunajudi.pdfIn PDF document text
    • http://changrung.com/ckfinder/userfiles/files/86878245224.pdfIn PDF document text
    • http://chromavials.com/d/files/27353273361.pdfIn PDF document text
    • http://jolanyee.com/upload/files/202109030705256312.pdfIn PDF document text
    • http://studiofranzoni.eu/userfiles/files/kewuxurunudanavofivako.pdfIn PDF document text
    • http://handlpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nabamaxipaduzalolalepel.pdfIn PDF document text
    • https://tamphuctriland.vn/upload/files/6525426928.pdfIn PDF document text
    • https://satbietthu.com/luutru/files/vopomidikemakex.pdfIn PDF document text
    • http://rosritual.su/app/webroot/js/ckfinder/userfiles/files/bowonumedaturiruzina.pdfIn PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210908202540.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/1f3i0nl0adop0orkrrum1elavk/74126427192.pdfIn PDF document text
    • http://sieuthimaynhapkhau.com/upload/files/kadilomifipinuwizazi.pdfIn PDF document text
    • http://ipublicity.cz/data/file/wesijegovikodasatifitekaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=pes+20+android+downloadPDF 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_off0000cfc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFC4 17744 bytes
SHA-256: 11ee0b60ebdc4e7243b7eed6407e12bfb2e9684d3c495ebccb15aec68115e61d
font_01_sfnt_off0000fe04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE04 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001161b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1161B 10472 bytes
SHA-256: db42463952a359ee7bf922cf2c4b381860bcd98d727da966ac96007787784f12