Malicious PDF — malware analysis report

Static analysis result for SHA-256 a23514ea1c51096e…

MALICIOUS

PDF

83.3 KB Created: 2021-03-25 09:57:37 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 7dc08f5f6a8d58a3f890a59bd4864a38 SHA-1: b8f81bfb81c5e2c4d35e7f7f5a48ffabd1e78d08 SHA-256: a23514ea1c51096edeb7ed79622722c5115402624ab16d6f5ff93adf4d20966d
186 Risk Score

Malware Insights

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

The PDF contains a link farm with 30 external links, many hosted on disposable domains, suggesting a phishing or SEO spam campaign. The primary URL `https://jumiwimov.ru/strik?utm_term=is+the+nook+tablet+still+supported` appears to be a lure for users searching for information about Nook tablet support. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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/strik?utm_term=is+the+nook+tablet+still+supported PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4403959/normal_60301dd2c20c8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445879/normal_5fd1ee2b17f6a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4415525/normal_5ff7b40e36d3e.pdfIn PDF document text
    • https://wimugedi.weebly.com/uploads/1/3/4/7/134725841/4543727.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451561/normal_604ba1a5a06b6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388432/normal_601331fbb9ed7.pdfIn PDF document text
    • http://zomolejefej.mywebcommunity.org/how_do_i_simplify_a_ratio.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4422908/normal_5fecf38b38b7a.pdfIn PDF document text
    • https://sojujigun.weebly.com/uploads/1/3/0/9/130969910/7330416.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384650/normal_5fe78e9450fef.pdfIn PDF document text
    • http://tofoxewesaxizuz.mywebcommunity.org/biogas_kotoran_ayam.pdfIn PDF document text
    • https://zuvofuguwapu.weebly.com/uploads/1/3/4/0/134042474/2231314.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495999/normal_600fa7c0476bb.pdfIn PDF document text
    • https://bunofavaluz.weebly.com/uploads/1/3/4/6/134661637/nadega_rebubawekes_pevulavuwupal.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/xutomoxu/24654421698.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8b3f8a81-f792-4242-8b96-aff4f7bfa05f/dagijivukalilotu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4cfd9275-4fbd-429b-a2ee-d8a9a7fd6040/finite_element_analysis_in_geotechnical_engineering_application.pdfIn PDF document text
    • https://s3.amazonaws.com/ganubifirigevi/cacti_templates_juniper.pdfIn PDF document text
    • https://s3.amazonaws.com/timeziso/82895611489.pdfIn PDF document text
    • http://jinugiwi.atwebpages.com/aisc_base_plate_design_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/fomudebipefasu/jozokifa.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fbbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBBB 5072 bytes
SHA-256: ddbb212f8911b13988cc62c3ab3688206abbac06039847e707b15a3169955aff
font_01_sfnt_off00010cd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CD4 10600 bytes
SHA-256: 141769b4ce30f44ccd94aff29751a6c96d63aabace5d2806700f73a4330d5199
font_02_sfnt_off00013143.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13143 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c