Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcffb8d613799cb7…

MALICIOUS

PDF

69.7 KB Created: 2021-10-04 01:13:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 00193955368976b00e7e73f02c87e25e SHA-1: fd8cc8739e78583b91e82858cff1d0e6920d59e9 SHA-256: bcffb8d613799cb74c3b68aa7bb376ef1a5c062b0e6b2c3acbc92307ad63139f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to other PDF files, suggesting it functions as a link farm. This pattern is commonly used to obscure the ultimate destination or to distribute further malicious content, aligning with phishing or malware delivery tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://oris-am.com/editor_up/mimosotafusig.pdf In PDF document text
    • http://fitviewer.com/files/file/tezowupexivogokebap.pdfIn PDF document text
    • https://sogelec-eng.com/files/ckfinder/files/39586892536.pdfIn PDF document text
    • https://adminico.nl/userfiles/file/nemubupajezenof.pdfIn PDF document text
    • http://0225674989.kad.tw/kads/ckfinder/userfiles/files/27272563090.pdfIn PDF document text
    • http://corporatiegids.nl/uploads/files/26624810676.pdfIn PDF document text
    • http://mjengo.org/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/51736456947.pdfIn PDF document text
    • http://bsinteriordesigner.com/userfiles/files/dapatamukefudijamisawug.pdfIn PDF document text
    • https://www.douggoodkin.com/admin/ckfinder/userfiles/files/rigepigufodoxiwawaso.pdfIn PDF document text
    • http://kastely-vacduka.hu/fileok/file/27969102122.pdfIn PDF document text
    • http://veterina-naslunci.cz/userfiles/file/razomikekefukikevujagoxo.pdfIn PDF document text
    • http://grupposcorcia.it/userfiles/files/tagozejimutazuloxosab.pdfIn PDF document text
    • https://booburger.myagenda.cz/pictures/editor/files/bexopen.pdfIn PDF document text
    • https://mobilpetrol.olajpark.hu/files/files/75314310884.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/45121207391.pdfIn PDF document text
    • http://esistore.de/userfiles/file/12446340457.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/5h40b11rs1jsn9uhhpg2ln2iom/notulomikaxojokidutejapug.pdfIn PDF document text
    • http://cmsrecuperocrediti.it/images/file/98314785509.pdfIn PDF document text
    • https://hebatkeren88.com/contents/files/nukagomegu.pdfIn PDF document text
    • https://onecre.com/images/content/files/pakimur.pdfIn PDF document text
    • https://vsetinrally.cz/userfiles/file/56648469108.pdfIn PDF document text
    • https://magnettoptan.com/upload/ckfinder/files/jufitodumoruduvemekelel.pdfIn PDF document text
    • https://thinkglobalcompliance.com/ckfinder/userfiles/files/nipilenav.pdfIn PDF document text
    • https://nhomphuongnam.com/upload/files/dokurela.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=find+the+derivative+ofPDF link annotation
    • 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_off0000b2c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2C0 10280 bytes
SHA-256: f20c81da925d132536a3ea5a237573d15365477f360676f514a742854cd35fd7
font_01_sfnt_off0000c9c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9C4 15556 bytes
SHA-256: 2b7aae2ef47deacd5fcb4ce9bf8bc63b90411d4236d501851755b203c3721cf0
font_02_sfnt_off0000f113.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF113 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1