Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e28f3993c4e60e2…

MALICIOUS

PDF

76.6 KB Created: 2021-04-28 09:49:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: 6738bfa9746a52434331a66c68aa4756 SHA-1: 8b93e3b94693fa386eed7e704abb6ee0397c61db SHA-256: 4e28f3993c4e60e27d869b72389a23aea0ea1b055bb799a4bde5dff20f2854b0
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting services, indicating a link farm or SEO spam operation. The primary URL, https://xajibur.ru/strik?utm_term=is+zojirushi+water+boiler+safe, suggests a lure related to product safety. ClamAV detected this file as Pdf.Phishing.Trojan, and an ML classifier also flagged it as malicious. No scripts were extracted, but the structure and URL patterns are consistent with phishing or malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://xajibur.ru/strik?utm_term=is+zojirushi+water+boiler+safe PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4468571/normal_6023da4016a56.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369775/normal_606dfc4e98f43.pdfIn PDF document text
    • https://cdn.sqhk.co/zuzipogowita/hcifqVB/21244157260.pdfIn PDF document text
    • http://graatorama.space/ways_of_the_world_2nd_edition_freemgrto.pdfIn PDF document text
    • https://cdn.sqhk.co/jaxugaveg/jeidXKa/74388275573.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4469641/normal_6016c4b6ee5e0.pdfIn PDF document text
    • https://cdn.sqhk.co/vemudumuxixu/kjhhfPj/41633339283.pdfIn PDF document text
    • http://carinsusa.info/spectrum_math_workbook_grade_8_free92cvz.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448536/normal_6009e274b0209.pdfIn PDF document text
    • http://experiment.website/langrisser_landius_guideeo0my.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376357/normal_604bb60941200.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://caa91486-5fcc-43b7-8b2b-5b817ae85bbe.filesusr.com/ugd/26bbcf_708d5d27300f492591a1538f9d02842f.pdf?index=trueIn PDF document text
    • https://ce322291-b3da-4cc2-ae0f-523e25daec44.filesusr.com/ugd/4530da_159bfe20f1d445548f24484da3139096.pdf?index=trueIn PDF document text
    • https://113c517c-d7b0-4b36-99d7-6722bcb7ef36.filesusr.com/ugd/8e66a5_ada9b395fca943819d7c9cec6267ce4f.pdf?index=trueIn PDF document text
    • https://2ac8321c-28d8-41c8-ac7a-99137a6fe030.filesusr.com/ugd/157ee0_d6e8dd616f824ffba9c504836ea3f7ad.pdf?index=trueIn PDF document text
    • https://51fd5013-30c4-43d1-89ce-86564632a3b5.filesusr.com/ugd/9f06f8_c627fbe029ec4ff08d59cbe29519eea9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/430aa81b-478e-4f41-893d-2826eb4f540c/katogetomirezivurawi.pdfIn PDF document text
    • https://5e73d190-47a4-4ead-99bf-7e9069f06a16.filesusr.com/ugd/55cc32_76b19eb44729437bbda81a08be05f2ac.pdf?index=trueIn PDF document text
    • https://9049409e-dcbb-43fe-b7cb-0f7a5d042cf1.filesusr.com/ugd/e59eee_7ead04a441494533917ba9f077b70da8.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9f54e74f-b850-4671-bb3b-019ab98e75f7/76619456619.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f0afd788-5de3-49eb-a70f-3b6757aac8bc/ti-83_plus_calculator_online_manual.pdfIn PDF document text
    • https://d525ee04-2a40-494f-8ba9-fee52f7b18ee.filesusr.com/ugd/8b8e24_14c008a4284b4da9839e2ea2bdcac2d0.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_off0000f056.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF056 5152 bytes
SHA-256: e60aade7ccd4c84988449c789fa82ef85db183910f3f7b35ed343bfe415a61e3
font_01_sfnt_off000101f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101F4 10220 bytes
SHA-256: ba220cc8c2c14e2048f83f40370d055a90c23b6e69557d02a86261261a44bec7