Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf1854698607b087…

MALICIOUS

PDF

76.5 KB Created: 2021-09-07 01:09:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 0b3ef48c2c823b53e533c38b6086c8f7 SHA-1: 4eddbb00ba33e79580a4e9d92c2bc53eb51d51c2 SHA-256: cf1854698607b08799a120a18ebcd935768596b7fb6b2d8cc7e855b842e8ac71
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute traffic. The ML classifier strongly flagged this PDF as malicious, and the presence of external URIs suggests an attempt to redirect the user to potentially harmful content. No scripts were extracted, but the overall structure and URL distribution are indicative of a malicious distribution or SEO poisoning campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://inwebjor.ru/uplcv?utm_term=hydrovane+compressor+manual PDF link annotation
    • http://cherriestattoo.com/ckfinder/userfiles/files/24992849130.pdfIn PDF document text
    • http://jingluo.net/uploadfiles/files/wudiwezegizilepimisajo.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/h5kf73lfn410j29eh0sl5p9vj6/fifelorute.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160bf2af0d5f04---68258335896.pdfIn PDF document text
    • https://spbmworld.com/anaeter_capital/siteadmin/userfiles/files/kimig.pdfIn PDF document text
    • https://brazilairporttransfers.com/ckfinder/userfiles/files/22442470847.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/efmk4esr7dp1psdaaevd70ujuk/15376782982.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e484cfe1d7f---palifupuwebebiwaju.pdfIn PDF document text
    • http://ilovemynewstemcells.com/clients/865932/File/75134062724.pdfIn PDF document text
    • https://andymullinscommercial.com/home/andy/public_html/ckfinder/userfiles/files/jukewabulamode.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/9363632993.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/ffed2351a43f50691d64bc44848d1c6a/zusegexizuwam.pdfIn PDF document text
    • http://vikohasanfiber.com/upload/files/7034017503.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608858bd70e2f---mokewuvemerabukameweto.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160744a7a3e78d---barusosajidisedol.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/19kah18b7rlhvu6j5fsbhb7fmn/padewevofiv.pdfIn PDF document text
    • http://forma8.kz/ckfinder/userfiles/files/12524857395.pdfIn PDF document text
    • http://apvn.info/userfiles/file/27331192609.pdfIn PDF document text
    • http://creative-format.com/upload/editor/files/nufegevuka.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608f8a899d013---62316268461.pdfIn PDF document text
    • https://yar-net.ru/userfiles/file/28432928511.pdfIn PDF document text
    • http://fruitvita.com/files/files/xefugejepaki.pdfIn PDF document text
    • 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_off0000c576.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC576 17848 bytes
SHA-256: 3079dcc1298ccad0a3de3b7bd97078f5738c12a7c642d3cda6a8ef3ff0337f81
font_01_sfnt_off0000f3bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3BB 10756 bytes
SHA-256: 00bbcb1ff921a5bbc30dc1ddea1c6c4608423ef868b2fac46e4c6c444f623baf
font_02_sfnt_off00010c6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C6C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1