Malicious PDF — malware analysis report

Static analysis result for SHA-256 b96a87d7730b3b9c…

MALICIOUS

PDF

133.5 KB Created: 2021-03-22 09:38:18 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 281a845191f9d0bf5ae978786ba88c51 SHA-1: d22d1e1874532cbe8c40937ef5d2b718487a3db6 SHA-256: b96a87d7730b3b9caa6af531fd58132bf4bf908c57cb8492006063ddf6d614b9
74 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many pointing to disposable domains, and a heuristic firing for a 'link farm' suggests a malicious intent to redirect users. The presence of a 'download button' lure and a high ML classifier score further indicate maliciousness. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a keyword related to software installation, aligning with a potential download lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 5

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://kuzutuzo.ru/wix?keyword=how+to+install+open+terrain+generator PDF link annotation
    • http://on24-system.club/kijetlawx8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4407571/normal_5ff856d4edaad.pdfIn PDF document text
    • http://oneitshop.pro/free_word_tracing_worksheets_for_kindergarteno94z0.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366956/normal_5fe30e12753f7.pdfIn PDF document text
    • https://mavezuwunokil.weebly.com/uploads/1/3/4/6/134627141/767376.pdfIn PDF document text
    • https://nogeduju.weebly.com/uploads/1/3/1/3/131398368/zunuxixalopoz.pdfIn PDF document text
    • http://wimazosuwoxugij.66ghz.com/malaysia_income_tax_e-_filing_guide_2019.pdfIn PDF document text
    • https://pibowalemarume.weebly.com/uploads/1/3/1/1/131164440/9026669.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393908/normal_5fe527e3d4d27.pdfIn PDF document text
    • http://smartradiobf.ru/dark_souls_remastered_guide_lobos6l97x.pdfIn PDF document text
    • http://palefazorubo.22web.org/pidodemodotusumazuwuw.pdfIn PDF document text
    • http://cyberlife.store/986970842779kfks.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414514/normal_5ffa6c1185519.pdfIn PDF document text
    • http://bostpolamos.site/lti_terases_grdasldd2l.pdfIn PDF document text
    • http://fomilexavekol.22web.org/vigibez.pdfIn PDF document text
    • http://lightly.store/conjuguemos_answer_key_indirect_object_pronouns9az7c.pdfIn PDF document text
    • https://lulegosepo.weebly.com/uploads/1/3/0/9/130969478/kepuboxubavozowasa.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/bafea769-4899-43b1-9120-8337a392cf96/55613931928.pdfIn PDF document text
    • http://mejufupivu.epizy.com/41915823962.pdfIn PDF document text
    • http://damaxokabipo.epizy.com/duwefujejuxal.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1427026c-1dbb-4054-819a-7f16b13028e5/jafosokunobuna.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001ba01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BA01 5040 bytes
SHA-256: 428ab48ce590935b22c32e3882fdee38153447c509aec15f6cf44d9aedb3af5f
font_01_sfnt_off0001cb46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CB46 11348 bytes
SHA-256: 9e944f4101369d78f41489abb48d09f5ced253f73d5fd95a9af10064d02d6fe7
font_02_sfnt_off0001f1f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F1F3 16204 bytes
SHA-256: 541fa2b6826b0add99b7d5a173ef1e6a5567607b5192f75b810eb17d6a563501