Malicious PDF — malware analysis report

Static analysis result for SHA-256 83c5b35d506ac27b…

MALICIOUS

PDF

82.2 KB Created: 2021-09-18 21:49:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: e7020ac73560436912051b446ae7ce2a SHA-1: aba4a7813b6c7fa80cf925bbc054dee2a793082e SHA-256: 83c5b35d506ac27b41f305c2d866a9adff36178aaecf15874dac2e10095ca9e2
154 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing sites or download further malware. The presence of embedded JavaScript (T1059.007) is a key indicator of the attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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
  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://cevhertemizlik.com/userfiles/files/48761858716.pdf In PDF document text
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/82417364725.pdfIn PDF document text
    • https://www.institutvzdelavani.cz/files/54474910447.pdfIn PDF document text
    • https://pecintajp.com/contents/files/pakilujakefegezotoja.pdfIn PDF document text
    • http://sweed-trans.eu/ckfinder/userfiles/files/85754508565.pdfIn PDF document text
    • http://hanauhrova.cz/files/rewuni.pdfIn PDF document text
    • http://gianniarnaudo.com/userfiles/files/somewu.pdfIn PDF document text
    • https://snpwachq.com/files/js/ckfinder/userfiles/files/lojomuwitunesapuxisivim.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613d8571d2361---jesupejas.pdfIn PDF document text
    • http://espaciocultivarte.com/ckfinder/userfiles/files/fuvazanopazo.pdfIn PDF document text
    • http://emilybarnes.com/DEVELOPMENT/VERSIONED/emilybarnes/trunk/sites/default/files/file/67299106507.pdfIn PDF document text
    • https://sharmtocairo.com/userfiles/files/zevisoravizometebogufo.pdfIn PDF document text
    • http://artetendasud.it/userfiles/files/nutakesomudilosejatirazar.pdfIn PDF document text
    • http://irinka.org/ckfinder/userfiles/files/zurovividexatu.pdfIn PDF document text
    • http://taigesw.com/upload/files/loburisubotefusofame.pdfIn PDF document text
    • http://rsti.biz/files/fck/file/76319784289.pdfIn PDF document text
    • http://hingliltd.com/userfiles/susizesopu.pdfIn PDF document text
    • https://conrays.ru/f/data/58603404359.pdfIn PDF document text
    • http://studiocommercialedelpiano.it/userfiles/files/68916384057.pdfIn PDF document text
    • https://moderator.lt/components/com_mijoshop/opencart/image/data/files/2784327009.pdfIn PDF document text
    • http://kientrucsangtrong.com/plus/files/5495931363.pdfIn PDF document text
    • http://maristaslardero.es/userfiles/file/89341759452.pdfIn PDF document text
    • http://kunmobile.vn/files/uploaded/20210905/file/76953247756.pdfIn PDF document text
    • http://studiozammuner.eu/userfiles/files/30424899218.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=android+zxing+custom+viewPDF 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_off0000dad6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAD6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2ED 10900 bytes
SHA-256: 99524a26823fce677b4235a9be25c84d89e10bd3117c9edf38573c19cdd07d6f
font_02_sfnt_off00010c17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C17 18004 bytes
SHA-256: 101fa5d026779d6b61c3d9310523fb4cc892cbe7007c932990888aecf64026a1