Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4f19c3815d8cd6c…

MALICIOUS

PDF

69.2 KB Created: 2021-06-22 17:54:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: ad4d1ad34de9ad1c9e6e220a9d3fe400 SHA-1: 0a03ea74d4a148bad87c9552ceeca584b90005e2 SHA-256: b4f19c3815d8cd6c07af43a22cf13e8ef3a31852dcfb615f02e07bfee56b0168
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other domains, likely intended to lure users to phishing pages or download further malware. The presence of multiple compromised CMS upload links and disposable hosting domains reinforces this assessment.

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 http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16095669228cd0---6054277312.pdf In PDF document text
    • https://thuaphatlaihoanghuy.com/uploads/files/finevumanadezapinat.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160942610539af---95332564447.pdfIn PDF document text
    • https://alate.org/admin/fckeditor/editorfile/gavaz.pdfIn PDF document text
    • http://jarosi.hu/files/file/55475033823.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/irkjig2gdrnak5ejt00gvfmn01/riridame.pdfIn PDF document text
    • https://tiklatakip.com/calisma2/files/uploads/konowozuxotakevare.pdfIn PDF document text
    • http://nessium.fr/userfiles/file/zomevivaju.pdfIn PDF document text
    • http://ajisushionline.com/uploads/files/36883205342.pdfIn PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606da249d9619---kasuseledasegob.pdfIn PDF document text
    • https://airbays.com/userfiles/file/82826309728.pdfIn PDF document text
    • http://ttccid.com/userfiles/files/buvikovejalux.pdfIn PDF document text
    • http://candientushinko.com/images/file/594942912.pdfIn PDF document text
    • https://www.freshstartdigitalmarketing.com/wp-content/plugins/super-forms/uploads/php/files/6050cbc4bae3fbb14757435a89d3f5f7/55812896071.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/jlg8bf0a2fssk7t3454i20isr3/pupoj.pdfIn PDF document text
    • http://tebsc.com/clients/84181/File/10169837363.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=nithya+karthigan+novels+free+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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c0c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0C5 5244 bytes
SHA-256: 6ce736da696c3b9c9a19736bfb54ce242ee2a7c327bccce829518cb686417b26
font_01_sfnt_off0000d2ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2AD 11004 bytes
SHA-256: 83916e1b6e24e57404d3425bf9f8fc945cfe66253efa4b602e735537a34fd832
font_02_sfnt_off0000f7e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7E3 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3