Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9405457ccb7fcbd…

MALICIOUS

PDF

95.4 KB Created: 2021-06-07 13:23:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 3de5aae63dedf06f86a8ddbfeb1c90fd SHA-1: e2114edee841d1e2191fa6d3c4561f4bc9b7b843 SHA-256: a9405457ccb7fcbd494b68c59f7785704a61cfb57d0cde407c8b9c6da398dcd9
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable hosting, indicating a link farm or SEO manipulation scheme. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and heuristics point to a malicious PDF designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://oniceh.ru/pbw?utm_term=to+kill+a+mockingbird+structured+notes+chapter+11 PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4409811/normal_5fde2fd5848af.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470688/normal_6024ed2fbe576.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405197/normal_603f954291ca3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481999/normal_5fe62a2184e19.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475864/normal_5fdaa8d00e591.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416331/normal_601c66e086705.pdfIn PDF document text
    • https://fizemovumevomuf.weebly.com/uploads/1/3/4/4/134491325/xidul.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411682/normal_604d80cb5b01c.pdfIn PDF document text
    • https://muvaxajipafe.weebly.com/uploads/1/3/5/3/135313420/509a89da0.pdfIn PDF document text
    • https://rivoliga.weebly.com/uploads/1/3/5/3/135311175/3849640.pdfIn PDF document text
    • https://vafiradas.weebly.com/uploads/1/3/3/9/133988778/9292133.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380395/normal_6069ee5b6260f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495985/normal_60379a8bdd421.pdfIn PDF document text
    • https://sotamepepoj.weebly.com/uploads/1/3/0/8/130874386/sepibajok-zimelevexukedop-navapotovova-marakanumosu.pdfIn PDF document text
    • https://vewejefimubi.weebly.com/uploads/1/3/4/1/134108794/fovivirabov.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/4591af96-3c54-4bc4-96b6-2df2ca8edbc8/kujikudotokegebat.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c915fb33-33a4-4346-8227-961e710a3620/33571117249.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/634c2d12-727d-4098-b110-3a885074f6fe/system_verilog_testbench_tutorial.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f9701132-97cd-4fb9-a617-fd4096b75516/maus_book_1_and_2.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/48741688-4f72-4630-9bce-292519c3f8da/the_norton_introduction_to_literature_portable_12th_edition_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/487adff6-fd33-47b7-ac59-20ec5f29efde/muxafedeligarusez.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b358f4c9-f333-47bb-b42a-a1f1e1981244/cuaderno_de_trabajo_5_grado_2020.pdfIn 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_off000137be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137BE 5692 bytes
SHA-256: 11713209aee07a16b43fd9b6331b036bc6d8af35737768c28cc4b5c27186a40d
font_01_sfnt_off00014ae9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14AE9 11072 bytes
SHA-256: a76f6a796df347d9ec7710ef56f65d6f47c23c9202cd9d449715cf5a3b5cedd4