Malicious PDF — malware analysis report

Static analysis result for SHA-256 d43b25be9b83c88d…

MALICIOUS

PDF

81.8 KB Created: 2021-09-15 11:51:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6e57a60bb7b7ef25748c97c90f647b7a SHA-1: 672742a886fdb5a74618777fe87b4d6dbee24ac7 SHA-256: d43b25be9b83c88d550c58bbc94e6ca3f953b1f67e59baec61056372911c7302
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://braveathlete.net/geektic/files/57182392887.pdf In PDF document text
    • http://one9five.com/userfiles/files/11415782403.pdfIn PDF document text
    • http://konberdbio.com/upload/files/67780788066.pdfIn PDF document text
    • http://www.wiz-fac.com/uploadImg/file/5985642230.pdfIn PDF document text
    • http://talani.nl/userfiles/image/file/jagepigirifakukigisosi.pdfIn PDF document text
    • http://csp.hu/editor_up/90391381306.pdfIn PDF document text
    • https://briljant-maleri.se/UserFiles/files/nokazuza.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/595b917b0bf0b420d53e22c7923e9e88/tikalenibakokunida.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16140fb3824537---tetezaratunopurekonaguv.pdfIn PDF document text
    • http://bridgestone-ice-cruiser-7000.ru/ckfinder/userfiles/files/22831509114.pdfIn PDF document text
    • https://songod.vn/uploads/image/files/95179861201.pdfIn PDF document text
    • https://kottayammedicalcollege.org/CMS/ckfinder/userfiles/files/77745556241.pdfIn PDF document text
    • http://letsbelegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/63832832579.pdfIn PDF document text
    • https://promenade-perpignan.com/userfiles/file/pakufewefamakokiruwazidod.pdfIn PDF document text
    • http://zoscm.zohukum.com/ckfinder/userfiles/files/tefede.pdfIn PDF document text
    • http://ed-union05.ru/files/file/62519918849.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/46992174312.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/d563d7ad10bcb6b205dadaf8e7d0165b/19763149481.pdfIn PDF document text
    • https://yk-tech.com.tw/ckfinder/uploads/ckfiles/files/sakifakolikewot.pdfIn PDF document text
    • https://novamakine.com/upload/ckfinder/files/25394513964.pdfIn PDF document text
    • http://luxcottage.ru/stroykamen/userfiles/file/44870570991.pdfIn PDF document text
    • https://media-get.ru/userfiles/files/sodusuzinoxanidonur.pdfIn PDF document text
    • https://vico-domrep.com/ckfinder/userfiles/files/dilavagu.pdfIn PDF document text
    • https://braindevelopmentmaps.org/userfiles/files/nusoneke.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=android+bild+herunterladenPDF 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_off0000d9ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9EC 10396 bytes
SHA-256: ee3014a502833ada6c2d352e180625ba6b71fe1f3e5a247817be72b5b380ceb2
font_01_sfnt_off0000f155.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF155 19352 bytes
SHA-256: 54d554263dd5db698023e45b3cd9fe6112f5c0ad883edd61333d0827d8b48050
font_02_sfnt_off00012175.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12175 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1