Malicious PDF — malware analysis report

Static analysis result for SHA-256 815a75d5a4633925…

MALICIOUS

PDF

79.5 KB Created: 2021-03-30 17:52:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 99a634c3c1d75ace71b909a499fa029d SHA-1: cba373c89c5a9bc2561eb3de75bd2e0b09bd46f2 SHA-256: 815a75d5a46339258790073e889e5f75e795234750329713b5ec94325c972473
186 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. It contains numerous external URLs, many pointing to disposable hosting, suggesting an attempt to manipulate search engine results or redirect users to potentially harmful content. The presence of a link farm and external URIs strongly suggests a phishing or SEO spam attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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.
  • 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://jumiwimov.ru/award?keyword=tecnicas+de+asepsia+y+antisepsia+en+quirofano+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4416939/normal_5fdf5468e16d9.pdfIn PDF document text
    • https://wuluvaxezipow.weebly.com/uploads/1/3/5/3/135393263/bb31eb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471971/normal_5fd916fd67736.pdfIn PDF document text
    • https://bekogome.weebly.com/uploads/1/3/1/4/131454098/9d15aa3.pdfIn PDF document text
    • http://francobusiness.com/four_corners_2_workbook_answer_keyk69ci.pdfIn PDF document text
    • https://xetetikagidol.weebly.com/uploads/1/3/5/3/135308020/viburalisek.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4425738/normal_5fcd25810adab.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417207/normal_5fe483e34536f.pdfIn PDF document text
    • http://gatorama.space/9680891546898y5t.pdfIn PDF document text
    • http://gufutaca6.xyz/winnie_the_pooh_book_set_amazonj60jn.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408170/normal_603af715e8ba4.pdfIn PDF document text
    • https://maladekokox.weebly.com/uploads/1/3/4/7/134745457/rodotamobawaf_vefoxip.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://99516632-72ce-40f3-a9a1-a01c91361c65.filesusr.com/ugd/e42c35_e750b005dbec41deb0b96b6361fc4303.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jevopemosod/57411307240.pdfIn PDF document text
    • https://s3.amazonaws.com/bisute/acdsee_pro_9_full_version.pdfIn PDF document text
    • https://528f6e5c-6927-42ef-b7a5-a8f9c349750c.filesusr.com/ugd/07b979_65003317b07e4d379b07d97a3f43b527.pdf?index=trueIn PDF document text
    • https://9ec55029-67b1-4fe0-9a5d-40fd638ac594.filesusr.com/ugd/dc5a51_e206b33e128d453d909813d56e2b0c3d.pdf?index=trueIn PDF document text
    • https://8458b573-1d6d-478c-912c-b10a972f31df.filesusr.com/ugd/150112_dfdf8487bb454d8baa2ee9c65677e075.pdf?index=trueIn PDF document text
    • https://14535e1a-360a-4d01-a655-fa33e115c80e.filesusr.com/ugd/b222ea_50424ad8b2774010a57a9246df2e72aa.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kitakilesa/60062375032.pdfIn PDF document text
    • https://s3.amazonaws.com/bezegoluzose/medicamentos_que_afectan_el_higado.pdfIn PDF document text
    • https://13a7c488-548c-4b48-b567-d2b0b9a3e1de.filesusr.com/ugd/85d67f_86c3e446da8545fc8eba824203cc7644.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/voropa/reporting_accidents_at_work_form.pdfIn PDF document text
    • https://19527f6f-7821-4b33-8e58-d909ab9a203f.filesusr.com/ugd/b18fc6_632aef2bf3ca40e88adaf6c3bb24aa88.pdf?index=trueIn 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_off0000f521.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF521 5292 bytes
SHA-256: 0cedcb4a5d2f99cf14bf16265f754a78f78e85a04288476ee53a81be9a0096b3
font_01_sfnt_off00010738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10738 12644 bytes
SHA-256: d727e724e8065aa0742df714ea3138c6a8dcd5c9876f8ad2c884f856ff446245