Malicious PDF — malware analysis report

Static analysis result for SHA-256 1d33f2ddf027c289…

MALICIOUS

PDF

72.7 KB Created: 2021-06-05 14:49:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 90af1ac8e372629e12d82ebb63831ada SHA-1: 5335de2b281e018efabb12de0ce472972a87fcba SHA-256: 1d33f2ddf027c28967cb167698f263dd66e87b390a98aba6bdb24b4ca2472904
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or SEO poisoning tactic. The ML classifier strongly indicates maliciousness. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards the document's primary function being to redirect users to malicious or compromised sites, likely for further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://chcial.ru/uplcv?utm_term=what+are+the+teachings+of+christianity PDF link annotation
    • http://amoy-art.com/Upload/file/nawogozonarew.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aaa39c3a71c---lenuxikokaruwa.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097ac2d7708c---deliwodaloreragisusije.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a607f5ce529---98405138356.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/541da9def810c0fb6172649659c05cbe/ranurexuxaxuz.pdfIn PDF document text
    • https://markeishahall.com/wp-content/plugins/super-forms/uploads/php/files/c8675fb0a83b6a00435296498dde0214/5169408274.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/63c6ac2422a09c52dd8494517ca2264e/mofoga.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/7c5e2cf0746623a42f3c15438ef26e30/genonubu.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b54de582082---joridexevotoneladotoxude.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/f8389050216f1654e5c672bf0a82eec4/vugabofexikud.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607faf1b1debe---saduwifu.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/rakigazoxewigudo.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1609c5b915808d---17590116835.pdfIn PDF document text
    • https://www.brightfieldbusinesshub.co.uk/wp-content/plugins/super-forms/uploads/php/files/na3gavteti1n7efbfn93peck35/16027115128.pdfIn PDF document text
    • http://evansmedia.ca/userfiles/file/dejamomeselop.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/109256fadc5061473df70acea444ebd5/nuxuruxozigi.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_off0000df80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF80 5228 bytes
SHA-256: e244df6f2da14e3d3ed5252269e8ba498dd2d95b139b92dc8a1305fc2a0d08fb
font_01_sfnt_off0000f15f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF15F 10628 bytes
SHA-256: 19082dfbd69eb8f4eb21f00fecdee45941ba2e3d843cd8cb69ad7157bfc4a60f