Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd9c3239806216c0…

MALICIOUS

PDF

97.6 KB Created: 2021-06-07 15:57:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 2ef9972f5a6985fac4ab9174e2eccc95 SHA-1: a4a13133d3133cdd2719f9bda0a0fab6b90c5804 SHA-256: cd9c3239806216c01fa55362ebeace66dc91f08586fe9619b6383b16cc99b56a
156 Risk Score

Malware Insights

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

The PDF file is identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous URLs, many pointing to compromised CMS uploads, suggesting it's part of a link farm designed to distribute malicious content. The document body, though heavily obfuscated, appears to be a lure related to IELTS preparation materials, indicating a phishing or social engineering attack vector.

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://coretry.ru/uplcv?utm_term=ielts+speaking+questions+with+answers+pdf+2020 PDF link annotation
    • https://hoakhanh.vn/uploads/image/files/87782722498.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606e2a92eac6c---45278224798.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/eb35b2a90294d5d37777f28fbc2f8d08/lureteb.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607678b6b5afe---18864513759.pdfIn PDF document text
    • https://kompaspt1.com/contents//files/74688518481.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d7ec313cb3---82342195793.pdfIn PDF document text
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/fd762719c3a03dd110e7be8280548025/55175551400.pdfIn PDF document text
    • http://scandirent-new.ru/uploads/assets/file/bekizudeminudorugejok.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/lejbf1pm8epgf41n34l1904a47/kepomoxo.pdfIn PDF document text
    • https://alsterparkett.de/wp-content/plugins/super-forms/uploads/php/files/s26c1lh0vb1dci5jmu9nfaps6i/biloxajijabefubikegi.pdfIn PDF document text
    • https://diversified-nj.com/wp-content/plugins/super-forms/uploads/php/files/82efa5c6b1c7f371c2989c0a69b6103c/momasi.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/c9f8f71d36e242d53414323378bc4fef/dezivovipunoxep.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/heqeaueluoofbshpot9blgc3il/32272466167.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/d2c8a2d3cc3004fa4470d8b4b949d6a7/topitogiperimolapunamoxam.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/956404cd6a15886ce6ce85acd2145549/64567750498.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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_off000141bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x141BC 5796 bytes
SHA-256: 6a052978c5c739afa4bc7550233751b9f051122c13be6b683ac5ae15587c7d53
font_01_sfnt_off0001557f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1557F 10444 bytes
SHA-256: c39655792bbd49d8e83bbd43180e20059e7b07e6d1c54e79b531867e1cbccb4c