Malicious PDF — malware analysis report

Static analysis result for SHA-256 aac0153764fbbb77…

MALICIOUS

PDF

73.3 KB Created: 2021-06-24 19:54:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: ead3bae3fcbc062115cdfb6ef9ad4224 SHA-1: 6ef4b9df419fb0c1afa1d2cfc8d5b788c8cde3d1 SHA-256: aac0153764fbbb779e741de9c13e282b33653d7efea7c4ba3f6d39a6d468fef9
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised CMS uploads, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, appears to reference a boiler manual, which is likely a pretext to trick users into clicking the malicious links.

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://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/2efc4d77b3e87bcc1d4c866a8bc8a36d/kekaxejojitole.pdf In PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/fpv63q2klhf1pg5bjd0bahkkc0/pojerar.pdfIn PDF document text
    • http://stjconsulting.it/userfiles/files/javasedir.pdfIn PDF document text
    • https://contact-house.com/fckeditor/upload/file/dojuj.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160bbb829101c2---foxejawodidar.pdfIn PDF document text
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/9tjli3mkh86kvd09e1eln6vkio/6178600924.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16093bb812a203---17162473032.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/40949335924.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/xosufakowivetonu.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/160926ad239466---15167573177.pdfIn PDF document text
    • http://ruilong-ironwork.com/CKEdit/upload/files/nufudovel.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b570e162ef0---tekuwixi.pdfIn PDF document text
    • http://sobinco.cz/ckfinder/userfiles/files/34437478628.pdfIn PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c81722cdc1---womuxufujozalir.pdfIn PDF document text
    • https://pypconsultores.mx/userfiles/file/xexeve.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/b2dece37bd4a514ed2e699cca619d263/rosakegigimo.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/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=peerless+purefire+boiler+manualPDF 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_off0000e33e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE33E 5188 bytes
SHA-256: f42c2ba1175ff6eddb3ce325c911f4a8bee5ef59498082fbcc311ee7d176f8bb
font_01_sfnt_off0000f4c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4C6 10416 bytes
SHA-256: d6ec2deb2535ffb2064b34d86e767fb06cb9111975f5d6d4181e8090826ccd86