Malicious PDF — malware analysis report

Static analysis result for SHA-256 9432e497a1c5b49f…

MALICIOUS

PDF

74.7 KB Created: 2021-09-28 12:47:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: dec1283aa130fe6a2fad14e3d6b30d1e SHA-1: 535dd09b44c1d1e8d7c01e05afd6b08f2222bcdb SHA-256: 9432e497a1c5b49f71dfd5fce8718f2778d74699698c2c1084265aaa1dc93f82
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to other PDF files hosted on various domains, many of which appear to be disposable or compromised. The ML classifier strongly indicated maliciousness, and the link farm structure suggests a campaign to distribute further malicious content or phish users. No scripts were extracted, but the PDF structure itself is indicative of a malicious distribution method.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://www.speeddating.lt/speeddating/ckfinder/userfiles/files/jurufogotokof.pdf In PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d88407c8ae---nazota.pdfIn PDF document text
    • http://www.logistiekverbeteren.nl/ckfinder/userfiles/files/97448104214.pdfIn PDF document text
    • http://ketphatthinh.vn/upload/files/60331674395.pdfIn PDF document text
    • http://ecoaga.com/documentos/file/dekurawuw.pdfIn PDF document text
    • https://volandovia.it/public/fileeditor/file/90501979292.pdfIn PDF document text
    • http://fu-xin.tw/uploads/files/202109130423412964.pdfIn PDF document text
    • http://isisthailand.org/file_media/file_image/file/7117232355.pdfIn PDF document text
    • https://marblo.ph/app/webroot/img/files/65616760893.pdfIn PDF document text
    • http://hairtransplantmangalore.com/uploaded_files/userfiles/files/57369986832.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16152cd142fb93---guvisesidiwulorel.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/16152148cf3e23---16201999622.pdfIn PDF document text
    • https://net-mex.hu/ckfinder/userfiles/files/24900550769.pdfIn PDF document text
    • http://bedrucken24.de/userfiles/file/62665077491.pdfIn PDF document text
    • http://chithanhplastics.com/uploads/userfiles/file/dosasovovox.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/16179453927.pdfIn PDF document text
    • http://ccsl.asia/files/27774895574.pdfIn PDF document text
    • https://simbhaolipower.com/images/file/tiroki.pdfIn PDF document text
    • http://blueleaves.ru/userfiles/file/fetuw.pdfIn PDF document text
    • http://mp-hd.de/data/aktualnosci_imgs/file/loniligixusilevuxe.pdfIn PDF document text
    • http://milwaukee.center/userfiles/file/91152063370.pdfIn PDF document text
    • http://status-go.net/gfx/userfiles/files/suwavavazopetovowuw.pdfIn PDF document text
    • http://kibunajcc.com/ckfinder/userfiles/files/raguluboxixilozivuzep.pdfIn PDF document text
    • http://xdata.pl/app/webroot/img/ckf/files/winijuzawulexobirapulowov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+update+tablet+android+versionPDF 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_off0000b87f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB87F 10768 bytes
SHA-256: 61dcb69497b312a63bdd0b2aa363e61fcab0f75342ab6fef6b2b45f75d4cf0ba
font_01_sfnt_off0000d129.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD129 20364 bytes
SHA-256: e48b8d5f83c32ea4e042e34cd4fa34c7f42714b1d08d3195576069bdac3f1d38
font_02_sfnt_off00010487.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10487 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1