Malicious PDF — malware analysis report

Static analysis result for SHA-256 8de3b35af31eb1ac…

MALICIOUS

PDF

78.7 KB Created: 2021-03-23 17:24:01 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 187e5699b647682a37181f152b34bc1d SHA-1: 25c23e3792bdfe9ec13b6a0b7a1cffbcb14f3378 SHA-256: 8de3b35af31eb1ac350f2cb2243cb6aa913ecf0448570d8182837ebc4552241c
186 Risk Score

Malware Insights

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

This PDF document functions as a link farm, containing numerous external links disguised as search results for refrigerator water filter replacements. The primary malicious URL identified is https://jumiwimov.ru/strik. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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/strik?utm_term=kenmore+coldspot+refrigerator+water+filter+replacement PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4450418/normal_5fcf822110747.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421461/normal_5ff1f6ee0c623.pdfIn PDF document text
    • http://firolinulaka.22web.org/aditya_hrudayam_in_tamil.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4402247/normal_5fcdfebd2c5b0.pdfIn PDF document text
    • https://xizuxikeg.weebly.com/uploads/1/3/0/7/130740292/tinewidekapugun_lasekimosomez.pdfIn PDF document text
    • https://gadolelexuzited.weebly.com/uploads/1/3/4/4/134486477/406732.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413465/normal_604959be8d1db.pdfIn PDF document text
    • https://vomerigovelaj.weebly.com/uploads/1/3/4/9/134901888/kewunozamiso.pdfIn PDF document text
    • https://nadenekaf.weebly.com/uploads/1/3/0/7/130739264/kuxeporujonot.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383464/normal_6011287e04dc1.pdfIn PDF document text
    • https://pegepujime.weebly.com/uploads/1/3/1/4/131453637/b9e63.pdfIn PDF document text
    • https://kifeketefisub.weebly.com/uploads/1/3/5/3/135347095/d6bc618c5e24.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://53f03ce6-db0b-4f41-9bfc-6956ba41e1f4.filesusr.com/ugd/727e0f_5b03f206f6aa4d69aaec7bd3e87c2f66.pdf?index=trueIn PDF document text
    • https://34e2f0dc-0077-42bd-a047-efa2502e92af.filesusr.com/ugd/8a05ec_b4b8f208b46e47a79028eee81291afd7.pdf?index=trueIn PDF document text
    • https://5c2df1de-05ea-4e17-9aa3-38adc7ce3153.filesusr.com/ugd/ddd609_4a51eeb89c9b470384c0302acb5442c0.pdf?index=trueIn PDF document text
    • http://posexafose.epizy.com/creative_company_profile_design.pdfIn PDF document text
    • https://2d130471-2a64-48ba-87cf-8f1e86c6acad.filesusr.com/ugd/9c43ec_0f7e1422b6224794ae36d5d3cd48645a.pdf?index=trueIn PDF document text
    • https://b46c4cda-4951-41c0-816f-bbf02eee4d9b.filesusr.com/ugd/4ff992_c11620d8476140ba8ade323b0d498e21.pdf?index=trueIn PDF document text
    • https://67dec473-0a9c-497c-80b1-62a4c84c5046.filesusr.com/ugd/0aab01_4f7b38e6320f4f12828e08c12ecc999f.pdf?index=trueIn PDF document text
    • http://bodupizul.epizy.com/commando_training_program.pdfIn PDF document text
    • https://d4078116-a2d5-466f-97e6-20d899f6ca30.filesusr.com/ugd/576447_64f8eddcd5894f9cae41057f3e2dfc24.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_off0000f572.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF572 5536 bytes
SHA-256: dae753ebc5d5e618430b5fd27fd6c139a315cac21d9e2036088516dbbf432db8
font_01_sfnt_off0001084a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1084A 10744 bytes
SHA-256: 2f870cd705dcd0ca19b7335cf4c5d8c20a4f871e7e2f282df4f7f027104617fa