Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e3cfe93cc763b08…

MALICIOUS

PDF

103.2 KB Created: 2021-09-08 09:20:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: e44c1444ab2f9f87443a29bfa8e7fd5a SHA-1: 8a53a908913bb4cbc6a092311cb87037f5aa1fbd SHA-256: 4e3cfe93cc763b08d11fa40a9baea78481e11eaee03a3ae99dec9bf54a45b841
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to compromised or disposable hosting. The ML classifier strongly indicates maliciousness, and the link farm structure suggests an attempt to drive traffic to potentially harmful sites. No scripts were extracted, limiting the analysis of direct execution vectors.

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 http://50wj66.com/clients/a/af/af9d65f11c1965a5434adcd4cd578f00/File/34235803554.pdf In PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ba5f52ed3ef---48416725368.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/subilujejikakozedu.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/3754544520.pdfIn PDF document text
    • https://sikahaiphong.com/images/news/files/kudosupale.pdfIn PDF document text
    • http://rebeccaosborne.com/uploads/40254146190.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/d6984d4bd026522c1af8ca5bf18abf6e/titunigufebab.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606f55417a038---wilufukubatewusivelip.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16120c8d5952a2---26069335839.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/45877647285.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1612d916e3539f---kabagutubuze.pdfIn PDF document text
    • http://barsugo.com/ckfinder/userfiles/files/lugate.pdfIn PDF document text
    • http://smithmaloney.com/clients/3/32/32eae1a42220421eddab78da2f55685d/File/xefutikewemaxewi.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160846d9f932a5---79485872307.pdfIn PDF document text
    • https://deniz-sogutma.org/img/userfiles/file/nalawataxitefunosoxigu.pdfIn PDF document text
    • https://www.andreivieru.com/ckfinder/userfiles/files/lepupo.pdfIn PDF document text
    • https://cakenflowersonline.com/userfiles/file/kawilefuwoxaj.pdfIn PDF document text
    • http://diplomat2014.ru/ckfinder/userfiles/files/nosopisewuretumijijik.pdfIn PDF document text
    • https://sahodayabbsr.com/test/fckeditor/file/18491519574.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bce1dba89fc---sezikusuw.pdfIn PDF document text
    • https://www.hsbofmn.com/ckfinder/userfiles/files/33223988483.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=franz+kafka+il+processo+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_off00012d10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D10 10644 bytes
SHA-256: 8f8b11ef66373410a192e588f6a496536c8e3cf98604bcef49bd44c691033552
font_01_sfnt_off00014582.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14582 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015d94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15D94 18944 bytes
SHA-256: 21abe0ffecbdf7812a79bc59a6b11e82cc10ba8f69c8f5b0e8301d0f212f2939