Malicious PDF — malware analysis report

Static analysis result for SHA-256 a51402bc8f689ba9…

MALICIOUS

PDF

79.4 KB Created: 2021-09-18 18:03:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5f10494c7afd322bdbf0afd51f356f7d SHA-1: 6f58341644baf1cacfc1f64a30bc1e6f410778e9 SHA-256: a51402bc8f689ba9df5ee9dff9cbf6b34b84806ca602e74bdfb49bc90103c8e3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to external PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports the idea that these links are used for malicious purposes, likely to distribute phishing content or malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 5

  • 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.
  • 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://kingcraftviet.com/uploads/ckfinder/files/babanupitiguzomu.pdf In PDF document text
    • https://dichocungtoi.com/userfiles/file/siwikatenajugagudoruke.pdfIn PDF document text
    • http://recviem.ru/img/upload/24479480020.pdfIn PDF document text
    • http://top-caster.com/userfiles/file/bafimekibodigisamok.pdfIn PDF document text
    • http://1-sanya.com/blog_images/blog_/file/zomulotebudolok.pdfIn PDF document text
    • http://nagymester.com/userfiles/file/jedob.pdfIn PDF document text
    • http://mayinmaunhat.com/upload/files/larawimureke.pdfIn PDF document text
    • http://gibisch.org/files/files/xipaj.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/161300bcecdc94---ronekudi.pdfIn PDF document text
    • https://fablab808.com/nbloom/fckuploads/file/furikavapelikegidexofowi.pdfIn PDF document text
    • http://originalbau.hu/imagesfiles/50100312792.pdfIn PDF document text
    • https://dm288.rs/slicice/file/zebomuditaganexigiduzu.pdfIn PDF document text
    • http://benly-carson.com/product/files/35725512499.pdfIn PDF document text
    • https://www.bevillelecomte.ovh/ckfinder/userfiles/files/72013924483.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/tinazoludureda.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9cb14fab3---lepadafis.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16145f98c43b0c---26935104120.pdfIn PDF document text
    • http://studioferrato.it/userfiles/files/63293761831.pdfIn PDF document text
    • http://vinhthuanvietnam.com/upload/files/8347187398.pdfIn PDF document text
    • http://vietnam-intraco.com/webroot/img/files/92650027439.pdfIn PDF document text
    • https://debcopharma.com/userfiles/file/bixijipovaxizewido.pdfIn PDF document text
    • http://jtravel.clickis.kr/FileData/ckfinder/files/20210904_EA84A829F2AFC560.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=show+me+my+phone+storagePDF 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_off0000d0ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0BA 17968 bytes
SHA-256: d364e1336dd1ba72e7890cc0f88ecee48f040f98a3b3ccead187a1763b902bca
font_01_sfnt_off0000ff63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF63 10836 bytes
SHA-256: d0c4b5ce8a3c42f0d6593af56acdacebcbcc2a63614ae35e0fd4202815ecdb4a
font_02_sfnt_off00011852.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11852 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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