Malicious PDF — malware analysis report

Static analysis result for SHA-256 688f5d0d152708f1…

MALICIOUS

PDF

77.9 KB Created: 2021-03-19 10:26:54 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 3863fe494551d0d05d138965c4c465d7 SHA-1: b5974561f9ceaeff127bd8ed9443e8bcb264837a SHA-256: 688f5d0d152708f1ffd048d380a5f852a7b6fb2e6cf1662185711e3dd6c793e3
184 Risk Score

Malware Insights

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

The PDF contains multiple embedded links, with at least one pointing to known malicious redirector infrastructure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document body is heavily obfuscated and appears to be junk data, suggesting the primary function is to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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 links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://yafferge.ru/award?keyword=livro+associativismo+e+cooperativismo+pdf In PDF document text
    • http://samewejasaka.iblogger.org/retinorupejogezijapo.pdfIn PDF document text
    • http://daating19.site/fofiledojuuzw4m.pdfIn PDF document text
    • http://hook-up.fun/jopukiferasogupumaaodvh.pdfIn PDF document text
    • http://dupadevoz.22web.org/hunters_hill_public_school_uniform.pdfIn PDF document text
    • http://soribowunalosu.22web.org/zanukizel.pdfIn PDF document text
    • http://netzamka.ru/evinrude_6_horse_outboard_motorz3lk0.pdfIn PDF document text
    • http://naturka.space/nazonedijazarosovogiwasurfcf6d.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://samanofi.epizy.com/xububadivolib.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/02785e12-4987-44e8-ba44-131c1cdde8ad/63685303663.pdfIn PDF document text
    • https://s3.amazonaws.com/xufaxoferugod/5325247985.pdfIn PDF document text
    • https://8ed6bd9f-de2b-4923-b7df-82f95eb18a03.filesusr.com/ugd/7fa32f_460ce92ff0164f95911ced1c2d8f3642.pdf?index=trueIn PDF document text
    • https://f9fc249e-2e6a-4908-9eb0-88005465a50d.filesusr.com/ugd/2530ee_8367ba746e1f44cfb75c0e7d9e841536.pdf?index=trueIn PDF document text
    • https://d397443b-80d0-4e74-967c-4ce830ee3754.filesusr.com/ugd/0a76f0_e5f1ed9ff7744d3ab15b4447edb18b46.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7614fee9-b31d-4cd2-9803-db14b3e7b619/pie_chart_exercises.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1fb85b8b-65a7-4005-8ec6-8c4d4a1e7efa/50795402244.pdfIn PDF document text
    • https://cf075d60-af7c-4c71-a16c-5c8c125a9bb7.filesusr.com/ugd/cc03df_78b3a9aa4fe14e22bb11edb7a899ae82.pdf?index=trueIn PDF document text
    • https://85ed388a-52e0-4e79-9737-9d4b769dda71.filesusr.com/ugd/bb10c5_9590d33ba1564a52990e69ff6f8fc805.pdf?index=trueIn PDF document text
    • https://cd29ef07-728f-4a0b-b57b-23e770395c36.filesusr.com/ugd/f14cf6_bdf9cbb87e2341d78bf3c348f1a0527f.pdf?index=trueIn PDF document text
    • http://wevovodoneto.epizy.com/virazagosuronoga.pdfIn PDF document text
    • https://s3.amazonaws.com/wixatax/darukafipodi.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2B0 4952 bytes
SHA-256: d8ce7aef88b2cd2a36d53bafa5717366184469a00b0a003ec549c8db6977e5af
font_01_sfnt_off0000f391.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF391 13048 bytes
SHA-256: 2e10d4eab9d81467d761e4ba89329dccd9bad66654199ad68c8ae2ba3d545bf9
font_02_sfnt_off00011a8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A8E 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333