Malicious PDF — malware analysis report

Static analysis result for SHA-256 5355a9b1621eed73…

MALICIOUS

PDF

101.7 KB Created: 2021-06-13 12:06:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 5c3e59388dee20c6b100c5108fa86cc2 SHA-1: 2ac5b700fb17630d5e2e738f19dc38844f995501 SHA-256: 5355a9b1621eed73d999ce817c743ff97a5d54fa4d882bd7aed7a816361fc988
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan delivery mechanism. It contains numerous links to compromised WordPress sites, suggesting it's part of a link farm designed to host and distribute malicious files. The presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest the document's primary purpose is to redirect users to malicious content or downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://krisoc.ru/uplcv?utm_term=download+lucid+dreams PDF link annotation
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf045767e7---zumufovuwasalixerawiliz.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/6d2rfs11k7alktemt9gjiirlj0/wewumidaditigevolebimexen.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/d013fe5daa9a647aa2fb98c86561cbbb/84989155197.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/03f5535a17f259bb33adcd83c575f645/duximubusoduvunug.pdfIn PDF document text
    • http://aeronautike.com/userfiles/file/96569644397.pdfIn PDF document text
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/540be5b065d737cfedc399a55e4b41d3/winipimejapevela.pdfIn PDF document text
    • http://payassistinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071a6cf1335e---97540350680.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/e5272c214027cb225b873881c90c48f5/gimuzavaxotexatonepive.pdfIn PDF document text
    • https://pointsourcegroup.com/wp-content/plugins/super-forms/uploads/php/files/38d1e7048044ee76437c0ae5ad783693/padanifefuzekir.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160ba068aaaf5a---53751022941.pdfIn PDF document text
    • https://archltginc.com/wp-content/plugins/super-forms/uploads/php/files/f8363f51ec1c2d79ef262eb7871a884c/sometalaxipelolil.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ebfb35797d---33612049638.pdfIn PDF document text
    • http://cerescommoditiesltd.com/Images_upload/files/managemulefebel.pdfIn PDF document text
    • http://aranykoronakft.hu/userfiles/file/fejufanobiges.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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_off00015003.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15003 5176 bytes
SHA-256: 105579ed0489b52abc50a03d2e2e870e2c898cd123813c333dcd023ac76a68c1
font_01_sfnt_off000161a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x161A1 12964 bytes
SHA-256: 2337fb1b1fa614bb8d68f8f2116892b5259725e7dc23a9a26cf81ae9dc1ee494