Malicious PDF — malware analysis report

Static analysis result for SHA-256 f2ef3facf75d0523…

MALICIOUS

PDF

69.3 KB Created: 2021-09-09 08:25:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 46fbc5bd64c61ba6895052f071accdb1 SHA-1: c51d48cc10ebcda4d8b55926a802fbb90065d640 SHA-256: f2ef3facf75d05232067ce37d9b407b51c6a766f303a1f782603bf97c38ac6f9
104 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple external URIs, many of which are part of a link farm pointing to potentially compromised WordPress upload storage. The ML classifier strongly indicated maliciousness, and the presence of JavaScript suggests an attempt to execute malicious code or redirect the user. The document body is heavily obfuscated and unreadable, but the heuristics and URLs point towards a campaign designed to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://koovappadyscb.com/ckfinder/userfiles/files/bunemapazepofanafupikanoz.pdf In PDF document text
    • http://nanobubblevietnam.com/uploads/userfiles/file/35340305406.pdfIn PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/somaletaf.pdfIn PDF document text
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16132f9c94d959---80331814262.pdfIn PDF document text
    • http://ledins.lv/cms/file/zafiponasufegodewiweli.pdfIn PDF document text
    • http://reckdance.pl/userfiles/file/sobufozatuloro.pdfIn PDF document text
    • https://jlgardner.org/home/jlg/public_html/ckfinder/userfiles/files/15065578428.pdfIn PDF document text
    • http://sandsflooring.co.uk/ckfinder/userfiles/files/vimagoxojurumetabixu.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/3dd3fc301f626c54b45b62d3fba7c98c/wibujabawomixowulobopivoj.pdfIn PDF document text
    • http://etcpremium.com/userfiles/files/4318173190.pdfIn PDF document text
    • http://haenuri.net/ckupload/files/xatixujajipa.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/gdp0vlv6fqfasmb3v0kdh7i6g3/50551717518.pdfIn PDF document text
    • http://salman-is.com/userfiles/file/mikave.pdfIn PDF document text
    • https://seikai.jp/free_images/files/sabufaxowozen.pdfIn PDF document text
    • http://baove24h.info/upload/files/navatiwiwinudogibosur.pdfIn PDF document text
    • http://uptownfallschurch.com/uploads/files/9186724107.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/segajuxajowabunodekev.pdfIn PDF document text
    • https://senfina.top/uploads/files/nexidonupewuve.pdfIn PDF document text
    • http://hopkim.vn/upload/files/14137806134.pdfIn PDF document text
    • http://cuborh.com/natelinhanew/js/ckfinder/userfiles/files/81917261392.pdfIn PDF document text
    • https://frontivo.ro/userfiles/file/jugopenawikapafunufuxake.pdfIn PDF document text
    • https://gulfsupremesa.com/ckfinder/userfiles/files/33285642704.pdfIn PDF document text
    • http://hyosangjo.com/userfiles/file/20210908111406.pdfIn PDF document text
    • http://tochalco.com/uploads/files/54588549208.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=neutrino+free+followersPDF 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_off0000b489.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB489 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC9B 14576 bytes
SHA-256: ed86917cccdffdbb646178ad44232dc135a7f7df00f7ef11de067d2ad62373bd
font_02_sfnt_off0000f0d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D1 10208 bytes
SHA-256: 7468534cce8da35f1b78435ba461eb40fb722743f275564650dd208ec29ffe31