Malicious PDF — malware analysis report

Static analysis result for SHA-256 e488283597fcb85b…

MALICIOUS

PDF

72.8 KB Created: 2021-09-16 18:31:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 49f1e8f26025fa59c7f8cece5a87112f SHA-1: 676a2273e2953f426e5e481c8e8be6bce1225e1f SHA-256: e488283597fcb85b1e15c35e11dbc6f585eabcece26c3365a3ebd1144fb183c8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which are hosted on disposable domains and utilize UTM parameters, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a malicious document, likely used as a spearphishing attachment to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • 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 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://krisoc.ru/uplcv?utm_term=custom+rom+for+mi+a2 PDF link annotation
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c71f48eaa8---5166644600.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16134ff30e3b23---95357572715.pdfIn PDF document text
    • http://visit-pune.com/userfiles/file/49495742624.pdfIn PDF document text
    • http://taemyung.com/data/upload/file/59518253902.pdfIn PDF document text
    • https://shian-jin.com/UserFiles/files/misumafawabosis.pdfIn PDF document text
    • https://intersat.lv/files/file/vovaganoxu.pdfIn PDF document text
    • http://www.arborvitae.cz/ckfinder/userfiles/files/86194365444.pdfIn PDF document text
    • http://cu-mbc.com/ckfinder/userfiles/files/zidovomevabapabiwawip.pdfIn PDF document text
    • https://whiteplacard.com/UserFiles/file/70802962817.pdfIn PDF document text
    • http://form4concrete.ru/pics/cont/file/nexexojolesanotixaruro.pdfIn PDF document text
    • http://espressobuilders.com/app/webroot/files/userfiles/files/pamupogapas.pdfIn PDF document text
    • https://mexico-airport-transfers.com/ckfinder/userfiles/files/16674309633.pdfIn PDF document text
    • http://thingsantiquesla.com/userfiles/files/patuwinezen.pdfIn PDF document text
    • https://agape4u.org/userfiles/file/rejojuge.pdfIn PDF document text
    • https://tdfstore.it/file/witapimupomiragirures.pdfIn PDF document text
    • https://euforbiabulgaria.com/uploads/pages/files/49826157000.pdfIn PDF document text
    • https://nazragame.com/calisma2/files/uploads/36562944474.pdfIn PDF document text
    • http://archinfo.ru/uploads/file/ramabobewapeva.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/14489673520.pdfIn PDF document text
    • http://skupka54.ru/upload/m/96531474474.pdfIn PDF document text
    • http://talcmanagement.com/uploaded_files/userfiles/files/gemedekabomutewofazunikez.pdfIn PDF document text
    • http://shopcode.ru/uploads/file/kosamatosugesetimun.pdfIn PDF document text
    • http://cloudinfo01.smartevolve.com/images/ckeditor/files/21335900774.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bc85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC85 10344 bytes
SHA-256: 9ba2137fcc61cf6eacc8c52c6a5a8dadd2d9a6937e90d98e2a6e8fa98be839c5
font_01_sfnt_off0000d3fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3FD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC0F 16216 bytes
SHA-256: b315056023f24567c0fbaed7ef74fdf79989117059b0cef3468eabc627ddaeca