Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8bbff726150e98c…

MALICIOUS

PDF

71.5 KB Created: 2021-09-25 23:28:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 34f6b30b379967e3e2696c6618dc2e21 SHA-1: 75ed282696b5a022b89fbbcf31231dfda9049996 SHA-256: f8bbff726150e98cb006d0751234ea5ef285ea3bb0c44ce0532bf8532221b85a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. It also features a link farm with numerous URLs, several of which point to compromised CMS uploads or disposable hosting, suggesting an attempt to obscure the final destination. The ClamAV detection and ML classifier further support its malicious nature, likely as a phishing lure or a downloader for further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://jamalcar.com/userfiles/file/88144880792.pdf In PDF document text
    • http://auto4-spb.ru/public/images/ckfinder/files/48082525456.pdfIn PDF document text
    • http://denprokhorov.ru/images/file/zewuvoluxugisu.pdfIn PDF document text
    • http://vp-dmsh.ru/admin/ckfinder/userfiles/files/3601985194.pdfIn PDF document text
    • http://cuboni.com/uploadfile/hong202109070944438101.pdfIn PDF document text
    • https://gryf-wet.pl/ckfinder/userfiles/files/1097826123.pdfIn PDF document text
    • http://studiotecnicopinto.it/userfiles/files/59847292243.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/70c67ba60654991e5ddf6605e983c5c1/13224007872.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613fff53a11e5---vumubobiwotaseriwu.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/86002562491.pdfIn PDF document text
    • http://upsshop.ru/ckfinder/userfiles/files/bideperaxikag.pdfIn PDF document text
    • http://janjoling.com/public/ckfinder/userfiles/files/ripivosebapewosom.pdfIn PDF document text
    • http://studioaba.net/userfiles/files/14400475723.pdfIn PDF document text
    • http://bibliotekaszamocin.pl/img/upload/files/nobemevakurozulazebibitox.pdfIn PDF document text
    • http://111-orte.com/testarea/cwsCMSlight/media/files/9546219526.pdfIn PDF document text
    • http://casaperferiesantamariagoretti.com/writable/public/userfiles/file/56121967775.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/migobufolaxurexomodosubi.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/a0c54febad5d6238e790789466af4946/kobupeboruxilogo.pdfIn PDF document text
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/46685364964.pdfIn PDF document text
    • http://mabifitness.it/userfiles/files/xotopuzejolexexavafegipo.pdfIn PDF document text
    • http://lamachine.nl/userfiles/file/nefoxatibumurogof.pdfIn PDF document text
    • http://kdsonline.org/userfiles/file/vabuguruguw.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/f3e0fc7235030edfb2580bb37d8124c9/70038975859.pdfIn PDF document text
    • http://oshcongregation.com/userfiles/file/letewivujawimazewal.pdfIn PDF document text
    • http://le383.com/uploads/files/wugufudesosorumo.pdfIn PDF document text
    • http://farmaciacogliate.it/userfiles/files/69968220117.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=streaming+film+tokyo+ghoul+live+actionPDF 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_off0000b271.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB271 16344 bytes
SHA-256: a72b051a665350006343d26f56cf54d9acca54532ead3d2c114df9a1dbb4d837
font_01_sfnt_off0000dcd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f4e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E9 11064 bytes
SHA-256: c6db603b1a503f62190969a76a3ad44447aeae4173e3b40e3c674db41b737fa2