Malicious PDF — malware analysis report

Static analysis result for SHA-256 41ac9de83f0184c6…

MALICIOUS

PDF

76.6 KB Created: 2021-06-21 00:49:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: e043f3cb887d0edfce97ca815eb0fb0a SHA-1: 44251e64c966a23299772a62576d36eeea0d8687 SHA-256: 41ac9de83f0184c6e31988c1b21e890d1fe365b7dd48c732cd776399fb6b4687
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b40ff50344d---56137015972.pdf In PDF document text
    • https://www.sixteengrams.com/wp-content/plugins/super-forms/uploads/php/files/27g7kqqj520egms0ll8l932etl/49584368221.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071d723a92ac---91304567351.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5fbcceceb9---89106196796.pdfIn PDF document text
    • http://homeopathyhongkong.org/files/14791009936.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/mulitavelamirurilu.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608e2e1ff23e5---tavusavesetujo.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0423bed744---kijolenazuraxunanoloximo.pdfIn PDF document text
    • http://guides2alpes.fr/uploads/file/60433661505.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5b142659e7---bumasele.pdfIn PDF document text
    • https://plentis.eu/ckfinder/userfiles/files/4478889016.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/019d64dbc191227ce867e817821782ab/54673768681.pdfIn PDF document text
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/8628078f79dbaf90f211f69ae3523f54/13289167245.pdfIn PDF document text
    • https://ofertaromania.ro/ckfinder/userfiles/files/fesajezatakitunukusupu.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/b44e0c27849d2947ecf892f8c5ea7939/jomunebukafilumev.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/~3/1KS0DP0cxss/uplcv?utm_term=the+mummy+1999+full+movie+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_off0000ede5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE5 5284 bytes
SHA-256: 8013a31e903210e852fc087e28231da7549f1884077819c19afff5db35333e0e
font_01_sfnt_off0000ffe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFE1 11144 bytes
SHA-256: 0468b3c4299bdb879bd3930ca16a27e2e89488b7bc0361883cfba9dadda3b1bb