Malicious PDF — malware analysis report

Static analysis result for SHA-256 55276f134cdb4e47…

MALICIOUS

PDF

75.1 KB Created: 2021-09-03 17:59:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 97952f97785753e47aaeeda123a90136 SHA-1: 5215ebc8529b6fb02d9df4867ab1c20ea7d179d0 SHA-256: 55276f134cdb4e47adcbd88cdc71b22322b52e48557678c38e53788cb795e58a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm heuristic suggest it's designed to lure users to external, potentially harmful, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/nl1435ola1nqc0cal57egkvoqn/63797954298.pdf In PDF document text
    • http://psychanalyste-gard.fr/ckfinder/userfiles/files/77583919037.pdfIn PDF document text
    • http://albatrossmrn.com/konadnew/userfiles/file/dadidonot.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/pufikimot.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a15f30f1608---61091922774.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/5963824115.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f8c5657a29---pobozi.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/oq44q7kqktolm41aj03rsfur8l/mufugulab.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160983fa471955---18114459455.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607266750257b---54560972413.pdfIn PDF document text
    • http://altiro.nl/home/tjerk/file/subuva.pdfIn PDF document text
    • https://bahceneryaman.net/public/content-images/files/92113423887.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/b5241a6dd7c87152e5be87ad335ebfd6/29144938331.pdfIn PDF document text
    • https://sbufficio.it/file/81599396087.pdfIn PDF document text
    • https://www.renfrewareahealthvillage.ca/ckfinder/userfiles/files/gemijurenerulikipame.pdfIn PDF document text
    • http://sieuthicayxanh.vn/webroot/img/files/sesosasupewab.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dbcbf625147---fapukajolinepawavux.pdfIn PDF document text
    • http://yesilderecine.com/admin/editor_resim/file/19835153986.pdfIn PDF document text
    • http://www.verneteco.com/ckfinder/userfiles/files/50203442810.pdfIn PDF document text
    • https://mbbs.hr/files/14949649540.pdfIn PDF document text
    • https://mvmdigital.gr/files/files/gukanowogiwowimot.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16081c6633a048---37589197567.pdfIn PDF document text
    • http://olynskiconstruction.com/pics/file/53145237480.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=dividing+whole+numbers+without+remainders+worksheetPDF 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_off0000c1d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1D9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F0 11180 bytes
SHA-256: 051d0ae62422ed48206714c5c33c45cf6f57e990b62705e299ebf083ef52c86d
font_02_sfnt_off0000f3b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B4 16736 bytes
SHA-256: e30a5ea5cd7be8ca1a8976c169265299f3e32fcf506b1bfbb65ee2a8b9b1f27e