Malicious PDF — malware analysis report

Static analysis result for SHA-256 e6391afcc36eba43…

MALICIOUS

PDF

76.3 KB Created: 2021-06-23 20:27:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 9b35787693a9eab93731057e0e820387 SHA-1: e9efc6770ed1b205ef7385a52196337e31896db3 SHA-256: e6391afcc36eba430e520d8178468920215bfb7dd0cbf81e125a001960612bfe
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites, which likely serve as part of a link farm to distribute further malicious content. The document body is heavily obfuscated and contains metadata indicating it was generated by wkhtmltopdf, suggesting it may be part of a larger 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://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160ac1f0145987---xiwemanejilisad.pdf In PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/c8ddf9bd0fff4b325969a7a3abf2871d/jofuvijolobobozo.pdfIn PDF document text
    • https://www.explosivo.gr/wp-content/plugins/super-forms/uploads/php/files/08f90356ab2950db5195b64ba26e45c0/39097006953.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093136350b4d---tolipuxi.pdfIn PDF document text
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1606f68b654370---60150723856.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160bbeb9dc9c76---2499279579.pdfIn PDF document text
    • https://airshow-bg.com/file/39880750832.pdfIn PDF document text
    • https://www.qlsny.com/wp-content/plugins/super-forms/uploads/php/files/823c1b73001396467bad79ebb8b652a7/zaxisokusepoputizaw.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/99990372597.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8c3608a0f---16224215196.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/aa1dfb1cc11ad71c92616ba28458c9fc/fekomiwotolaxokewekovuxir.pdfIn PDF document text
    • https://charqueadaboavista.com.br/wp-content/plugins/super-forms/uploads/php/files/a23bf3e3f412ebf4b4d351785012cfb1/75424083287.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/bofatajetitapofixekad.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/160982f49e4a05---foviputalarogokepegeko.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=tense+formula+chart+in+nepaliPDF 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_off0000dbd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBD9 5204 bytes
SHA-256: 8e3d1161f94d7b9591c43838a633710c6519d4677c07f774c2e192583bb54de3
font_01_sfnt_off0000ed5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED5D 11304 bytes
SHA-256: 803d55949730504e430490a3df1124fa3111fc7aeb33ef25bbf37bfb8a779041
font_02_sfnt_off0001135b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1135B 4496 bytes
SHA-256: 7137d3af8df8d283cf5a66d2b6fbcde7c91fc4cde26fedb8c535a665c5677876