Malicious PDF — malware analysis report

Static analysis result for SHA-256 4871f99290f552b2…

MALICIOUS

PDF

40.9 KB Created: 2020-06-11 18:27:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-24
MD5: a346672f579ad2ca4781d4fd85f36052 SHA-1: 11fce03fd749a27352e9884c7f11d2cf9bbd8805 SHA-256: 4871f99290f552b2aa26d55921c5b80b74065ae4c286673f0acda548ef7122ed
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external links to other PDF files hosted on various domains. This behavior is indicative of a link farm or a distribution mechanism for further malicious content. The ML classifier strongly supports the malicious verdict. No scripts were extracted, limiting the ability to determine specific payload delivery or execution methods.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 4

  • 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.
  • 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 http://markinthemiddle.org/uploads/1/3/0/2/130288316/130288316.html#wilt+pdf+espaol PDF link annotation
    • http://oleoleburritoexpress.com/uploads/1/3/0/6/130639141/sijuroto_miwugoxoje_lakipuzamuki.pdfIn PDF document text
    • http://knowyourthoughts.com/uploads/1/3/0/5/130588477/mowawilaf.pdfIn PDF document text
    • http://jinmumianbaijialeyoujiama.br3h.com/uploads/1/3/0/5/130590278/wetuzaxub-gafaxon-vixolose.pdfIn PDF document text
    • http://montgomerytattoos.com/uploads/1/3/0/4/130490875/d7d1098d8a43f2a.pdfIn PDF document text
    • http://taystails.com/uploads/1/3/0/6/130620710/zevavelagu_fupuwojonexozo_takox.pdfIn PDF document text
    • http://easyclicktoearn.com/uploads/1/3/0/5/130551729/16b351a539dbc.pdfIn PDF document text
    • http://unknowncrits.com/uploads/1/3/0/8/130814083/xebufanix.pdfIn PDF document text
    • http://starspangledbabe.com/uploads/1/3/0/8/130813601/8867b9bf7.pdfIn PDF document text
    • http://cpanel.ashleymartinportfolio.com/uploads/1/3/0/6/130621720/vizakitukanolo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://miteduxom.files.wordpress.com/2020/06/13968664578.pdfIn PDF document text
    • https://fenazudedo.files.wordpress.com/2020/06/83049896229.pdfIn PDF document text
    • https://levejen.files.wordpress.com/2020/06/vunizukizekimigalumireva.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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000748f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x748F 10636 bytes
SHA-256: e0ceb1195d540d16f7f94b91b6ea202863bd2e02d9baf3c0bf5c44f6ebd99614