Malicious PDF — malware analysis report

Static analysis result for SHA-256 16bb0704627aff54…

MALICIOUS

PDF

81.0 KB Created: 2021-09-07 07:26:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a0e23ec0a45355736e7945e2552a1a16 SHA-1: 76fc4556d50f636fa19890180e20827ab16efadb SHA-256: 16bb0704627aff5480bece42076e1874cfdc4f6a40fe92ef2cec792e505a5952
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains a link farm with numerous URLs, several of which point to compromised WordPress upload directories and disposable hosting, suggesting a phishing or redirection scheme. The document body is heavily obfuscated and unreadable, further supporting the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • 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.
  • 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://bursac.net/userfiles/file/tepefak.pdf In PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/c292dc25eab9909a3e1dc4e132014708/84021686299.pdfIn PDF document text
    • https://snoman.mb.ca/ckfinder/userfiles/files/21761743630.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/jajamijidifovotu.pdfIn PDF document text
    • http://lubrifianti-auto.ro/files/file/4445851365.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/kujin0ppn197gkoe7u36v2il3v/vusaruketilezenawe.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16075bcc0a08f5---velisewakalugemimajaja.pdfIn PDF document text
    • http://rhoptik.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/77664952209.pdfIn PDF document text
    • http://hoteldanang.vn/uploads/images/files/47622158805.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f1a9fbef750---5269819636.pdfIn PDF document text
    • https://gulfcans.com/home/madarmun/public_html/gulfcans/images/bulk_images/files/37259213108.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16091b24305369---xuzaz.pdfIn PDF document text
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/54b0afus4r1s1omuh38hsj0i8v/80857564185.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fb4a29b07e---neragul.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f3b3c2508e---3921149368.pdfIn PDF document text
    • https://www.sacda.org/wp-content/plugins/super-forms/uploads/php/files/dg45od4nfo1trdq3uqsj09abq3/8911255681.pdfIn PDF document text
    • http://venusland.vn/app/webroot/img/files/doxowat.pdfIn PDF document text
    • http://mgocsm.in/userfiles/file/parudukonajomavisune.pdfIn PDF document text
    • http://shihtzufurbabies.net/clients/d/d3/d383cf0c90cf2d2391705d5438694b4c/File/82360432351.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4797935631---kisefemitukajilakifoz.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7d43da886---madevaloze.pdfIn PDF document text
    • http://ghefootmassage.com/fckeditor_userfiles/file/fudatisitoxaxejonutug.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=basic+electrical+engineering+mcq+book+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_off0000d650.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD650 11392 bytes
SHA-256: 6016ef7e84d0cddf03a88e3bf664346f80c10c9183dcfa6fbf0c717136dc2b19
font_01_sfnt_off0000f06d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF06D 17560 bytes
SHA-256: eff886d9f91e9d180c5f19c212349000c7affe5e970555a434663ccf7cf57610
font_02_sfnt_off00011dc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1