Malicious PDF — malware analysis report

Static analysis result for SHA-256 397c01ab40688b72…

MALICIOUS

PDF

80.8 KB Created: 2021-09-16 18:34:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1d425d1d134b7da703b0db3b087419ad SHA-1: 07296e2a05d37f2dae3404cea1f34cbe47fb317a SHA-256: 397c01ab40688b72d351d1a07e4336e0b3549c0047827f785323fe8df3be6b58
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. The document body is heavily obfuscated, preventing analysis of its specific content, but the presence of many external links strongly suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • 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 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://www.teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/bedawijevixunodimofa.pdf In PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/c6e9c39cc2370a4f5836a3c50f16324b/15498533928.pdfIn PDF document text
    • http://vigova.vn/Images_upload/files/ridebolejefa.pdfIn PDF document text
    • http://paykaaluminiya.ru/ckfinder/userfiles/files/66650649465.pdfIn PDF document text
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/dudefakuke.pdfIn PDF document text
    • https://zagi.hr/files/47217105485.pdfIn PDF document text
    • http://4x4autok.hu/userfiles/files/jobiso.pdfIn PDF document text
    • http://dc-a0dcf319a153.breakthroughsport.com/userfiles/files/68434121789.pdfIn PDF document text
    • https://groupekheidri.com/ckfinder/userfiles/files/34316029635.pdfIn PDF document text
    • http://miryangpension.com/FileData/ckfinder/files/20210901_0BA12E3D225AEDAA.pdfIn PDF document text
    • http://elcolono.net/userfiles/files/85030421904.pdfIn PDF document text
    • http://montoaneli.com/ckfinder/files/3760101058.pdfIn PDF document text
    • https://batdongsandothanh.vn/luutru/files/70246252154.pdfIn PDF document text
    • https://istruttorecinofilo.it/userfiles/file/gipevewibumiwegoxibati.pdfIn PDF document text
    • http://lnv-cnc.com/userfiles/file/rokolosizitonex.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/16140d7ccf1bc2---vamamuperefupikusuvelub.pdfIn PDF document text
    • http://revize-elektro.info/UserFiles/File/41246581694.pdfIn PDF document text
    • https://saptabangunmanunggal.com/indomobils/upload/file/36115210586.pdfIn PDF document text
    • http://studioingtassinari.eu/userfiles/files/redebamamixarukilu.pdfIn PDF document text
    • http://kronospan-mofa-hungary.hu/editor_up/80094064977.pdfIn PDF document text
    • http://studiocalcinoni.com/userfiles/files/ferigepa.pdfIn PDF document text
    • https://stotex.rs/files/55616720426.pdfIn PDF document text
    • http://www.celso.org/download/99696595329.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=holt+mcdougal+pre+algebra+practice+workbook+answers+pdfPDF 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_off0000d692.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD692 16904 bytes
SHA-256: a7ce60477facf4413db11302cc61287e723e9200821d9e266616f05dbdac87f6
font_01_sfnt_off00010250.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10250 11372 bytes
SHA-256: 5e9b185d11e3b6900f281f3f45a9b2e8922891995a1e4ebde4dde5b527c04262
font_02_sfnt_off00011cac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CAC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1