Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4a651473cb98150…

MALICIOUS

PDF

83.2 KB Created: 2021-04-29 22:53:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 97e118d5681ffefa2249eb49e742db9a SHA-1: a93319bc2ed2d6a1de290363424aa872c9b2e1a7 SHA-256: f4a651473cb981500584b9d899b76f40d26de253ac4fb867cdf15984c51548cf
196 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with a critical heuristic identifying it as a PDF link farm designed for SEO. One prominent URL, 'https://jacksth.ru/strik?utm_term=igt+slot+machine+error+codes', is flagged as a redirector for free-download phishing. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for distributing further payloads or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://jacksth.ru/strik?utm_term=igt+slot+machine+error+codes PDF link annotation
    • http://visumetanopigi.iblogger.org/biocontrol_of_fungal_diseases.pdfIn PDF document text
    • https://cdn.sqhk.co/bexuxoxabim/giB8Xhe/39675361262.pdfIn PDF document text
    • https://cdn.sqhk.co/mizipudi/bdVjeK4/10223690899.pdfIn PDF document text
    • https://wazafalesozem.weebly.com/uploads/1/3/4/4/134498636/1510702.pdfIn PDF document text
    • https://wugisawenepo.weebly.com/uploads/1/3/4/7/134749509/fedunazusa-zetirarovupobig-direfoxivon-bofofuzoza.pdfIn PDF document text
    • https://cdn.sqhk.co/tajudozizif/jaGhjjb/blood_pressure_by_age_calculator_nhs.pdfIn PDF document text
    • https://nalodewemutut.weebly.com/uploads/1/3/1/1/131164475/tefanexatin.pdfIn PDF document text
    • http://fajopapapabin.22web.org/50773559774.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/xapota/66775824989.pdfIn PDF document text
    • https://s3.amazonaws.com/nuvukivaxiren/the_monk_and_the_riddle_book_summary.pdfIn PDF document text
    • https://460eb545-5389-4aa9-9e78-d1074a8bca0c.filesusr.com/ugd/21a131_3006e26e0e6547c2978155c6a687adcd.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/resisuna/natefopa.pdfIn PDF document text
    • http://vowurosato.rf.gd/chacha_chaudhary_comics_in_bengali.pdfIn PDF document text
    • https://s3.amazonaws.com/gusule/witchery_shoe_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/zamemigojat/derivation_examples_word_formation.pdfIn PDF document text
    • https://s3.amazonaws.com/jukezeluf/28993239429.pdfIn PDF document text
    • https://f98f40d2-b649-4e6b-99af-b89bbf2331ff.filesusr.com/ugd/724bd4_8d7d5439558e46678bf4a3bd984996cf.pdf?index=trueIn PDF document text
    • https://297de083-771a-4730-a3b8-a2afe8c7d209.filesusr.com/ugd/47424f_50ca4223f2be42e38cd0fd6ab75e6682.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/pirofopafu/67471850336.pdfIn PDF document text
    • https://s3.amazonaws.com/sezebepit/24357245903.pdfIn PDF document text
    • https://b1b0174c-961c-4936-87f6-765e1132391e.filesusr.com/ugd/6cf804_01e3690fc26c43b0864bc768dda50c98.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xedewofuretujo/dewevupaf.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000102e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102E1 5288 bytes
SHA-256: b6c1b1b20ca113defede02dd5ed3b2009ff9729ef76a9d9ad3084441f1271e05
font_01_sfnt_off000114af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114AF 12116 bytes
SHA-256: 82e22cd34367c680c16d154df0f4c400f2c4ab5f765ffafab580575ff0a7a334