Malicious PDF — malware analysis report

Static analysis result for SHA-256 36d4f9ba0e2e7aaa…

MALICIOUS

PDF

83.4 KB Created: 2021-09-11 00:38:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 45101c0bfeb4cf8c3df0260eb6c5ac07 SHA-1: 44c7dbf4a112fa8c3557375bd1942d114928de82 SHA-256: 36d4f9ba0e2e7aaa00885b852642b939af5fc18c3a05a867efa266d9db05f8a5
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristic firings indicating it is a link farm and directs users to algorithmically generated URLs. ClamAV also detected it as Pdf.Phishing.Trojan. The presence of numerous external URIs, many hosted on disposable domains, suggests an attempt to redirect users to malicious content or phishing pages. No scripts were extracted, but the PDF structure itself is used to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://vitajeans.com/ckfinder/userfiles/files/wowosur.pdf In PDF document text
    • http://hanasushimenifee.com/uploads/files/79588484615.pdfIn PDF document text
    • http://cavusofis.com/images_upload/files/4132033187.pdfIn PDF document text
    • http://bresky.cz/res/file/mekupi.pdfIn PDF document text
    • http://carraracucinecomponibilitrapani.it/userfiles/files/gowasipe.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba1a302a18---23217046993.pdfIn PDF document text
    • http://rm-centr.ru/uploads/file/dejavaliro.pdfIn PDF document text
    • https://educationindiajournal.org/ckfinder/userfiles/files/vilenoxoporepanaka.pdfIn PDF document text
    • http://ballarioarchitetti.eu/userfiles/files/69938803411.pdfIn PDF document text
    • http://katour.ru/admin/ckfinder/userfiles/files/2724647659.pdfIn PDF document text
    • https://hotelharmika.com/assets/userfiles/files/papuj.pdfIn PDF document text
    • https://ihappywash.com/uploads/files/202109051646064375.pdfIn PDF document text
    • http://teplospectr.ru/images/files/75613158371.pdfIn PDF document text
    • http://unicaconsultoriarh.com/images/files/benenilodizomejakodekupuw.pdfIn PDF document text
    • https://partnermind.cz/images/files/87557095956.pdfIn PDF document text
    • https://reniuved.it/file/zulaliduruzanuvarilev.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/vol77q644dnsktfos9lamegim1/52273579078.pdfIn PDF document text
    • http://czdashan.cn/uploadfile/file/2021090406435373499.pdfIn PDF document text
    • http://pijntherapie.be/uploads/files/14202558870.pdfIn PDF document text
    • http://ucg-eg.com/userfiles/file/76279664265.pdfIn PDF document text
    • http://elma-itc.ru/!upload/files/93549259786.pdfIn PDF document text
    • https://ntpuvoice.com/ckfinder/userfiles/files/bedabozadiwufimipebafu.pdfIn PDF document text
    • https://sindhuinvestment.com/ckfinder/userfiles/files/xozirutawugijakiwi.pdfIn PDF document text
    • http://vhshf.de/File/zogemarukaduvimoz.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/83285755845.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=joker+hd+wallpaper+4k+for+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_off0000df43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF43 10576 bytes
SHA-256: 2f74a923376d0d8b3a0160ae511907d1174bb0a52ab714fc146311012efd1117
font_01_sfnt_off0000f763.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF763 18296 bytes
SHA-256: 14a54d70f549e4866f1b965556e1dbad337f07613d89dd1b2fdc3f2cbbcc9650
font_02_sfnt_off00012778.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12778 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1