Malicious PDF — malware analysis report

Static analysis result for SHA-256 153b8cf0f35b4e33…

MALICIOUS

PDF

71.9 KB Created: 2021-09-25 06:58:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 21308e7d4d6a9a1c5603b97251004691 SHA-1: f5ce6b7e18e814d356186d7baba7812abd70df24 SHA-256: 153b8cf0f35b4e33a4cbb5d5a41c166c3d154820bd10dd5890c06adcb1a2d200
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a link farm pointing to various PDF files hosted on potentially compromised websites, suggesting a lure for users to download content. The ML classifier strongly indicated maliciousness, and the presence of multiple links to disposable hosting reinforces the suspicious nature of the document. No scripts were extracted, limiting the analysis to the document's structure and embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://navoloki.mebel18.com/uploads/files/tikupigemuwi.pdf In PDF document text
    • https://alohasafaris.com/files/gigukafumowogozo.pdfIn PDF document text
    • https://cdmsig.com/ckfinder/userfiles/files/47148510772.pdfIn PDF document text
    • https://ooobelkom.ru/ckfinder/userfiles/files/27686181965.pdfIn PDF document text
    • http://xn--h1aaebajlcgx.xn--p1ai/sadm_files/wijesuxilin.pdfIn PDF document text
    • https://ever-progress.com/upload/files/kerevozazasitokogiwuget.pdfIn PDF document text
    • http://7seapharmtech.com/Uploadfiles/files/vexedika.pdfIn PDF document text
    • http://ecme.site/2015/vat/upload/files/27942275958.pdfIn PDF document text
    • https://fleuriste79.fr/ckfinder/userfiles/files/64391989850.pdfIn PDF document text
    • http://zhjpharm.com/upload/files/76551954191.pdfIn PDF document text
    • https://holcom-solar.com/webroot/img/files/zigafimitugijojakoziwok.pdfIn PDF document text
    • http://massarentearchitettura.com/userfiles/files/22940069611.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/tuvudomowavuzoje.pdfIn PDF document text
    • http://marinda.ru/pics/images/file/jijug.pdfIn PDF document text
    • http://news-hk.net/uploadfile/file///gefujovosafuruxewu.pdfIn PDF document text
    • https://castel.ro/userfiles/file/vapamodekux.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614bee435da24---sekuzutotemefales.pdfIn PDF document text
    • http://decom.pro/admin/ckfinder/userfiles/files/99728344463.pdfIn PDF document text
    • http://de.ruben.pl/ckfinder/userfiles/files/48254007589.pdfIn PDF document text
    • http://gymostrov.org/gymostrov/userfiles/file/38816880742.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/9a71be22122c82cf8ce75806aa0592d1/pededujigunu.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a06926e6cf---73263062300.pdfIn PDF document text
    • https://textosolutionslinguistiques.com/upload/editor/file/59013406743.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=quiet+place+2+download+torrentPDF 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_off0000b0db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0DB 10704 bytes
SHA-256: fabd9235578c8fcc7b10069593c34ba1688027811fb8698af2ed655a1a22de8b
font_01_sfnt_off0000c9b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9B7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e1c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1C9 18144 bytes
SHA-256: 3583c73fb477d49d57987b42c77ba4bca312538413c0c287595726b9ed348e15