Malicious PDF — malware analysis report

Static analysis result for SHA-256 defbf0972ab0b94d…

MALICIOUS

PDF

67.3 KB Created: 2021-06-20 14:52:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 980efb29d65bd150d8d093fe59bd9a91 SHA-1: 51700fb339d2e061dbe4dfe654049c6eb5d14e17 SHA-256: defbf0972ab0b94d70efca453aeba418264dc1d7b4e5c7279e12fd61773d1de8
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload storage locations and disposable hosting sites. The embedded URLs and the PDF structure suggest an attempt to exploit users by directing them to potentially harmful content or further malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160c86f6cd8f61---77449756830.pdf In PDF document text
    • https://iwnta.com/userfiles/file/fovanadizimixubusexunezid.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8432ed1a8---55592887658.pdfIn PDF document text
    • http://malopolskiszlakwinny.pl/upload/File/lelepigejukezepugefujiji.pdfIn PDF document text
    • https://nnt52.ru/userfiles/file/rosisokujotedawuvi.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/i3ffmn4km0ie2m5fhk5t1eleg9/89551115782.pdfIn PDF document text
    • http://ipceurope.eu/assets/file/5191730731.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607238a942f11---44733614054.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/ac7edfc5d95d2170cd6e5a0ed01b8342/saviwalajivinivuno.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/1292c4da086100f05c9eed3b0f9bc62c/sepikix.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160b940e0b76a5---bezow.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/c924f0764b894db82b93b1e5b02c4e59/56477126156.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b41fc6a26e---9363921669.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607a785a563df---34998349791.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/54cca96e9fac2702753bd833693e63a2/12720169672.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7a899472c2---ketegalibeposusifekatina.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/GLLx1DTH0VQ/uplcv?utm_term=battle+for+middle+earth+2+age+of+the+ringPDF 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_off0000ca0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA0E 5324 bytes
SHA-256: de2ef61728d9030b9fa0040553072f40ed3ab3345bac3d1ef0d955a3bb8ac1ad
font_01_sfnt_off0000dc00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC00 10088 bytes
SHA-256: 6bce615bc796e457c7b348f92f31cc5b6b3873e7f58be874645b0381d05bd639