Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f7de72b08b3e52f…

MALICIOUS

PDF

52.9 KB Created: 2020-06-19 21:50:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-07
MD5: 0b9e2cc68815bcbfea56ada870341a10 SHA-1: 6f032f1910c7b431ce5ea0f93defeabb4f98ac42 SHA-256: 8f7de72b08b3e52faaff094a95267422bf0ea3c4473c8cc428221b2a17e71e9a
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links to other PDF files hosted on various domains, indicative of a link farm or SEO spam campaign. The ML classifier strongly flagged this PDF as malicious. The document body contains text related to 'Cortisol connection diet pdf' and includes an embedded URL, suggesting a lure to external content. No scripts were extracted, but the extensive linking pattern is the primary indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://kyflowernseed.com/uploads/1/3/0/7/130775841/130775841.html#cortisol+connection+diet+pdf PDF link annotation
    • http://crossfit191441.com/uploads/1/3/1/4/131437029/tuxusopebata.pdfIn PDF document text
    • http://newcourtre.com/uploads/1/3/1/1/131164315/2ae0d.pdfIn PDF document text
    • http://visitnewburystreet.com/uploads/1/3/0/4/130475923/kekelevedamoxaz.pdfIn PDF document text
    • http://kenjoconsulting.com/uploads/1/3/0/7/130775267/verer_zupige_luvojadofirov.pdfIn PDF document text
    • http://amicoffeecompany.com/uploads/1/3/0/6/130639110/tabaraniri.pdfIn PDF document text
    • http://justbcosmetics.com/uploads/1/3/0/7/130740265/24af1d4c58.pdfIn PDF document text
    • http://awordtothewiseandcommonsense.com/uploads/1/3/0/4/130435619/8832663.pdfIn PDF document text
    • http://na-x.com/uploads/1/3/0/5/130588744/bokoxera_rizewefawuviw_dexasukoromizap.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off00008f5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8F5F 4748 bytes
SHA-256: 0e730f10a8432d623010768ab98603f39e993bae3dbcc6b91e19c1fdcce513ba
font_01_sfnt_off00009f89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9F89 13032 bytes
SHA-256: 5b61722e6229dd3dcaf6edc9091b7098a6b6fdc3a63f2d75d8ee0273580d4340