Malicious PDF — malware analysis report

Static analysis result for SHA-256 5ca630f3fcaa89c2…

MALICIOUS

PDF

76.1 KB Created: 2021-06-11 23:09:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: abd278476bae7645a650e461dd7278c0 SHA-1: 5a955594b34f050488fd572375eae4dd33370546 SHA-256: 5ca630f3fcaa89c2e58849c0b10b53c16eb882b4fdd6806cd258621fc519f45d
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which appear to be compromised or disposable hosting, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the presence of external links and the nature of the heuristics point towards a phishing or malware distribution campaign.

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://chcial.ru/uplcv?utm_term=a+little+life+by+hanya+yanagihara+pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608ab65ee7637---mejulewejelexupuvo.pdf
    • http://mintaialuminum.com/d/files/34488175167.pdf
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5f2c7f2aa36c695e05eaea7cdb640aae/3296016279.pdf
    • http://aarogyamedico.com/userfiles/file/74178323448.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/t3fektnhk4a07arm97ania1ac3/zidepe.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/fbn82einac3l7tn5ghsgjh9ufd/9542402149.pdf
    • https://arhometutor.com/userfiles/file/22866768730.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/rf60da099thpkjei4sc3njst96/42215912861.pdf
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a010b3632cc---93114774564.pdf
    • http://interwork.sk/userfiles/file/96868335260.pdf
    • http://alimentosldm.com/userfiles/file/terivi.pdf
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/23453371730.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed6a.bin
0f4adcc1ce483f91ccf0aabcb8f74f724e2d81e5ef4026ce4013d578cf1a994f
pdf-font-stream PDF embedded font (sfnt) at offset 0xED6A 5356 bytes
font_01_sfnt_off0000ffa8.bin
7a192609fc3238f31d517c5ed34de8df3d550436bfd46d047ca6d958d8689670
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFA8 10644 bytes