Malicious PDF — malware analysis report

Static analysis result for SHA-256 81726bccc90834f5…

MALICIOUS

PDF

92.0 KB Created: 2021-08-11 14:41:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 22bcb7f5b55d4a0e7b750dbcdfa248c3 SHA-1: f3965ab107546a65014d67765bba3b09b680baad SHA-256: 81726bccc90834f53a035f8bc4d54c711d9c99ffc478c8746200d142c094cf58
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan distribution attempt. It contains a link farm with numerous URLs pointing to compromised CMS uploads and disposable hosting, likely serving as a redirection mechanism to a final malicious payload. While no scripts were explicitly extracted, the nature of the link farm suggests an intent to exploit users through deceptive links, aligning with spearphishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://koyomisushi.com/uploads/files/judipanejosofepafarodarap.pdf In PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/33515854772.pdfIn PDF document text
    • https://bimetoor.com/basefile/bimetoorir/files/5427878997.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/84069be7328bd7b10ff36502293d6500/tufugogifabovo.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/160748c3c55bf8---73472425065.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160e9657304124---2232285984.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16111b333bd0cf---davirubi.pdfIn PDF document text
    • http://sillajen.com/fckeditor/_upload/file/54999509865.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/p82i1ebuvt76otvsqeg3fmg872/vomarabevenazorej.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/1e13cadd17ae777cb7c546da6e3c4284/mexusopuzorevitapojawev.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///mapaz.pdfIn PDF document text
    • https://kga-am-adlergestell-ev.de/kga/ckfinder/userfiles/files/nafotigijo.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1606eac2640d00---73224841282.pdfIn PDF document text
    • https://digireg.com/upload/guxebupabum.pdfIn PDF document text
    • http://ninda.vn/userfiles/files/94842469376.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160ddaaa6c3daf---gawifawaberadovalitovij.pdfIn PDF document text
    • http://ccshecea.org/upload/files/94626604152.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/nigax.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6921d3f485---8306118618.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/97tgiprmdehuekl4o9sq66qcdf/11104490015.pdfIn PDF document text
    • https://petikdaun.com/contents//files/60459440410.pdfIn PDF document text
    • http://ristoranteibucanieri.it/userfiles/files/sovopabo.pdfIn PDF document text
    • http://xn--90afqerdlt1f.xn--p1ai/admin/ckfinder/userfiles/files/jowewuguf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=describe+the+key+features+of+gothic+literaturePDF 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_off0001044d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1044D 10956 bytes
SHA-256: 6cb0a269e1bb2d03468d665e4fff4edde3261e9f66b7e77c450dee0c5181077d
font_01_sfnt_off00011df6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DF6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013608.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13608 16928 bytes
SHA-256: 73a9bb60ce29f9bf7d2ba5e56a703e62ee1d602d58fa4b1fc7dbfded6e36a795