Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4d89e84b97b0c82…

MALICIOUS

PDF

80.6 KB Created: 2021-09-09 01:35:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3a7563de20c4c597ac3bb78b9a97015a SHA-1: 8e534122a1195a1051f84190d7773142d5ee245b SHA-256: a4d89e84b97b0c82a7e415cc1524994d4a1e5918ff447737e8dc677ab2d4d944
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to potentially compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to exploit users through deceptive links, fitting the profile of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://psychotherapie-coeppicus.ch/userfiles/files/96605717266.pdf In PDF document text
    • http://logtech.cz/foto/Image/file/tarulojiti.pdfIn PDF document text
    • http://cocoon-source-harmonie.fr/public/file/kadegimolelilaw.pdfIn PDF document text
    • http://ccsup.co.th/uploads/ckfinder/files/pusurototokubu.pdfIn PDF document text
    • http://lex.tj/img/file/16477612301.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/8kuhsuhfc6c3nhff4n50kh6me7/74177296831.pdfIn PDF document text
    • http://mtcnx.com/upload/fckimagesfile/32869847313.pdfIn PDF document text
    • https://rijst.nu/userfiles/file/jinof.pdfIn PDF document text
    • https://dgssu.com/upfolder/e/files/20210908205303.pdfIn PDF document text
    • https://esofagopisa.it/userfiles/file/43601288257.pdfIn PDF document text
    • https://vietnaminsight.biz/ckfinder/userfiles/files/xomujodosinosoziku.pdfIn PDF document text
    • http://bdpq.hungminhits.com/files/uploaded/files/58413432540.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/161317ff61f122---pexerutodaj.pdfIn PDF document text
    • http://s4l.vn/storage/ckfinder/files/66697603652.pdfIn PDF document text
    • http://brunagabriele.it/userfiles/files/68265658892.pdfIn PDF document text
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/161356e746a395---20326882641.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/dotafezuzizatepod.pdfIn PDF document text
    • http://scuderieverdina.it/scuderia/userfiles/file/worowodabaluvu.pdfIn PDF document text
    • https://groupunsur3.com/contents/files/52597916934.pdfIn PDF document text
    • http://ever0036.com/assets/uploads/ckedit/files/20210901094925.pdfIn PDF document text
    • https://dienhoanghean.com/upload/ck/files/mijanexesipiluj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=power+bi+case+study+pdfPDF 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_off0000d74e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD74E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF65 10904 bytes
SHA-256: 977cd4eda580dcb93d4ae9b2a1a3377b5f316102c692898cd19555f4e4147b7e
font_02_sfnt_off000108a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108A7 17268 bytes
SHA-256: 1454777acca2414753070aee3d03cc5e122c25f83cdd957b26ddc7fb1a713f71