Malicious PDF — malware analysis report

Static analysis result for SHA-256 165dcd9b8680fc18…

MALICIOUS

PDF

85.4 KB Created: 2021-06-27 04:21:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: cb4f0b767476687321f60c3a9e801f56 SHA-1: 94dbe0f0c3b69cb0916adbb901451646bcd99363 SHA-256: 165dcd9b8680fc18e3904bf74373a839fc881c4c8c67a1219cf673f5bd97a50b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The document contains a link farm pointing to compromised WordPress sites, suggesting it is used to distribute further malicious content or phish users. The presence of multiple external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic further support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/171ba59d5695bd3469ab0138790816cc/xidarinetesezidusaponapo.pdf In PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/4oitll7gcnjio33km4m4nnoal1/83063177448.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608b301289bca---fekojuzuf.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/be37bdd880e5d4d2d7fc927ef35e4d05/nonufe.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/2828ce83c8b374e623c0b232bf589fb2/83531779015.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c21e1133f33---15683824896.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/b1f61df6273143b4c832e32c831412e7/86728276902.pdfIn PDF document text
    • https://waelfawzy.com/userfiles/file/In PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b4771b9de2---73207895723.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/33125e6b0bacf3e19b3c962d9cf033ae/82835106260.pdfIn PDF document text
    • https://www.apartamentselsllacs.com/wp-content/plugins/super-forms/uploads/php/files/2vjqv9r8nicetofqnb3vs4e470/redid.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16091d849a54f3---revemizalu.pdfIn PDF document text
    • http://barrybusiness-crm.com/ressource/devis-photo/files/40948693560.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608eceb5d9c9a---luxakafesujenefuzilo.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/jofegivofufe.pdfIn PDF document text
    • https://gelblighting.com/userfiles/files/pufalirinivo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=medical+name+for+dwarfismPDF 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_off0000ed46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED46 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010558.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10558 16716 bytes
SHA-256: 45a53a6b53f4dd158048ba52f53126d8132d599acc70d86693a972f59bdf34ed
font_02_sfnt_off000130ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130CA 10620 bytes
SHA-256: 8865ec09e6e1a98c0aa59a9e7ec91a8f3611f38307f98d52c7efdc26019baba3