Malicious PDF — malware analysis report

Static analysis result for SHA-256 d641bbb1554eae18…

MALICIOUS

PDF

70.5 KB Created: 2021-10-03 01:10:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 65e9ad00ecd98bf5d76ad684714cd83b SHA-1: cec7dd5283f21faa7edb58197fe3e8380deafe2b SHA-256: d641bbb1554eae18bf2459e6fed92b6a7bde35918c56e7ec1f4afbb0502f5fda
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier with high confidence. It contains numerous embedded URLs, many pointing to PDF files on various domains, suggesting a link farm or SEO abuse. One URL, https://shopexpert.com/app/webroot/files/userfiles/files/61294798319.pdf, is identified as a potential entry point to this farm. No scripts were extracted, but the PDF structure and embedded URIs indicate a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://shopexpert.com/app/webroot/files/userfiles/files/61294798319.pdf In PDF document text
    • http://tweddlefoto.com/files_contenidos/upload/files/lotojulodubukobamoripe.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/bopuxovipatotawukemipe.pdfIn PDF document text
    • https://oriental-kitchens.com/userfiles/files/37420651615.pdfIn PDF document text
    • http://hometextiles-consultant.com/ckfinder/userfiles/files/mimibaxa.pdfIn PDF document text
    • http://umbabox.com/userfiles/file/vunawarazegapabidufavamib.pdfIn PDF document text
    • http://onestep-tokyo.com/userfiles/file/53939617562.pdfIn PDF document text
    • https://thefertilizerproductionline.com/d/files/26185483403.pdfIn PDF document text
    • https://bselink.com/userfiles/file/perajukilupazepebizosobo.pdfIn PDF document text
    • http://lammermoor.net/imagenes/file/donubasev.pdfIn PDF document text
    • http://theponghop.com/upload/files/2967925708.pdfIn PDF document text
    • http://dogalakustik.com/depo/sayfaresim/file/mofopevutapubodovit.pdfIn PDF document text
    • http://ecme.site/2015/vat/upload/files/20263793498.pdfIn PDF document text
    • https://pincodehub.in/userfiles/file/giregasoxarizabebe.pdfIn PDF document text
    • http://thekitchendesignstudio.org/uploads/files/rasokuzajoxudewa.pdfIn PDF document text
    • http://somkuthyoptika.hu/editor_up/97090078768.pdfIn PDF document text
    • http://seamacros.com/upload/file/31106118681.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/161381098ec4da---7244890163.pdfIn PDF document text
    • http://huile-de-nigelle.info/userfiles/file/21241539581.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/5906004dc85ac7c9d7a129e98337f285/jadovutegatofaxezuj.pdfIn PDF document text
    • http://gzperson.com/uploadfile/files/22575304793.pdfIn PDF document text
    • https://printjet.pl/pliki_user/File/xizenu.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/mugofemojenekizas.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=the+bible+in+the+light+of+our+redemption+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_off0000b06a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB06A 16940 bytes
SHA-256: 17b03361ad79546a7b8f5b1811139ea344ab8f178410f14ef00faa647ed78a0c
font_01_sfnt_off0000dbd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f3e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3E9 10820 bytes
SHA-256: 60d3ebeb79f4856aa2ccb9443bd6967884d5860aff5729186f3febd529f829d0