Malicious PDF — malware analysis report

Static analysis result for SHA-256 5328928b9856e699…

MALICIOUS

PDF

74.9 KB Created: 2021-06-19 18:14:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: ecbd1acaa7c1c90e4b46ee50a6c87a03 SHA-1: 220dfd0ce848dc4a37490b7f37f208568926c9fd SHA-256: 5328928b9856e6996f582959bd79b8e5c282d8e51fdc2be15fd55e023dd00003
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It leverages a link farm hosted on compromised websites, including WordPress uploads and disposable domains, to distribute the PDF. The embedded URLs suggest a lure for downloading drivers, likely a pretext for delivering malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://xn----7sbakif2a3azdub.xn--p1ai/admin/ckfinder/userfiles/files/fisivalutirekiwekibek.pdf In PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c655485023---bomegugoguboxiwen.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160810edd0b55d---guzamanidinebeponefinusa.pdfIn PDF document text
    • http://abnicum.com/files/file/69231294216.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/gibitekobanuxumowel.pdfIn PDF document text
    • http://eros-arena-reutlingen.de/eros/userfiles/file/30050032223.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/c821b5936b5ace80ec05b30cb552096c/norinipazefok.pdfIn PDF document text
    • http://vtaky.sk/media/file/60579661759.pdfIn PDF document text
    • https://www.zulilighting.com/wp-content/plugins/super-forms/uploads/php/files/cc4f19a54b4551f8da060868439f56be/xoxutaxijuzulafotofuguda.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/92214395099.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/07553b069c9059968876cad4ae89bcb8/1045426616.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a447fd2501e---vosuximanoxosivoju.pdfIn PDF document text
    • https://chamsocmuihong.com/wp-content/plugins/super-forms/uploads/php/files/mes22vlc9pbnrqr55s7tmifng1/padodezuvurezuni.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ad936dd3352---vebitosod.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/e3b4310ba75453a702d55408fe388eb8/jivenesagap.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=ft231x+usb+uart+driver+windows+10+downloadPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6D4 5624 bytes
SHA-256: be48a16fae6f828950c7ebbaba183a9ab54dc394905bb2ab61bd73473873939f
font_01_sfnt_off0000fa21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA21 11024 bytes
SHA-256: 77e02b910a859af53736a2653fe4d3236185bb35c53dff76ac9b59269a244fe3