Malicious PDF — malware analysis report

Static analysis result for SHA-256 35f3f3936e51e576…

MALICIOUS

PDF

85.7 KB Created: 2021-06-09 22:21:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: f26922877b43d7f78984e6d580b0a3c6 SHA-1: 91b90c5f8eedf393889c66f46fdac3f0e1ecae06 SHA-256: 35f3f3936e51e576f3d7a457f00bd063a11412a6f24fe91ab9f875c39801550c
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress sites, suggesting a phishing or malware distribution lure. The embedded URLs are likely used to redirect victims to malicious content.

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://chcial.ru/uplcv?utm_term=b+boying+full+form PDF link annotation
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/9jjuv6j0qroljc0ubjbviqqub7/95032686239.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/187927fc5d1a534328158872f2812e41/xevovuwad.pdfIn PDF document text
    • http://lamachine.nl/userfiles/file/nutumado.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/0791e166ec2865163234ddc33f0a25bd/bokipawavapiwisaforidabe.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/j7fhsp0vks89q8h676j2i8nv3u/82409445531.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/52bcf0ff63ac43fb459e76d2f15aa4f2/53263604809.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072ff6adbaca---44315851150.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160b2368a5c3d6---97130049650.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b2ff0191407---kavonilimefamuwop.pdfIn PDF document text
    • http://buergerforum-tirol.at/file/76532185381.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/cdkhh95km7dttmr5h2cg0j56l4/girizesujexo.pdfIn PDF document text
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/a4e322f1bb2e2050d37d8fc4a58917f9/43858827142.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/ede006cd0c56bcbb7e24ebaf6393ffaf/popoz.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099de19b3621---63783488723.pdfIn PDF document text
    • http://stalmost.pl/userfiles/file/fukobirosapuforemodapiv.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_off0001136b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1136B 4988 bytes
SHA-256: a7455732c0980e8d5d04c32f2401148cd6848f9da1c469f9041ddd0866c20594
font_01_sfnt_off00012466.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12466 11260 bytes
SHA-256: 75dbe56b313aeb675919ed62aff2b29fef62137e5cfd56049216d174fe34466c