Malicious PDF — malware analysis report

Static analysis result for SHA-256 21e82eb0d2cb0543…

MALICIOUS

PDF

75.9 KB Created: 2021-09-16 18:36:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d777dd860c9521bebafa6d2bd3863a05 SHA-1: d2f1163e6c180769d710404885cd3ecbceced8ef SHA-256: 21e82eb0d2cb054346d1452901710388e5e1a17427d66a5351cce9eaca129b2d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs and is identified as a link farm on disposable hosting, suggesting a redirection mechanism. While no scripts were explicitly extracted, the PDF structure and numerous embedded URLs point towards an attack pattern involving spearphishing attachments designed to lead users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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 https://philabc.ru/uplcv?utm_term=lanka+cyber+news PDF link annotation
    • http://bisenzia.it/userfiles/files/99880865589.pdfIn PDF document text
    • http://frutapac.com/ckfinder/userfiles/files/86148794871.pdfIn PDF document text
    • http://floridare.ru/app/webroot/img/uploads/file/545004_jiwozivezedenafoku.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/diwenivetokefuxajamu.pdfIn PDF document text
    • http://giovanniseneca.eu/userfiles/files/dinutebobelibawu.pdfIn PDF document text
    • https://doosradashak.in/ci/userfiles/files/65509132667.pdfIn PDF document text
    • https://losaltos.com/wysiwygfiles/file/45945930635.pdfIn PDF document text
    • http://julianowka.pl/ckfinder/userfiles/files/41989095825.pdfIn PDF document text
    • http://pooq-design.com/app/webroot/fckfiles/file/60706792721.pdfIn PDF document text
    • http://fotografoenricogiampieri.it/userfiles/files/nozenigikujoxezitegozebu.pdfIn PDF document text
    • https://osiindia.org/ckfinder/userfiles/files/95695031087.pdfIn PDF document text
    • http://prvugkh.ru/uploads/files/pisajoj.pdfIn PDF document text
    • https://stl-log.com/htdocs/cljr/data/files/53264529237.pdfIn PDF document text
    • http://jucal.es/images/file/68346955081.pdfIn PDF document text
    • https://bluza-shop.ru/content/File/gisasoduzuzifalade.pdfIn PDF document text
    • https://mimpishiosatu.com/contents/files/tinamumusadezodaxu.pdfIn PDF document text
    • https://allcondosales.rodeodrivecondosale.com/userfiles/files/99011677680.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.net/filespath/files/20210911155000.pdfIn PDF document text
    • http://union.travel/ckfinder/userfiles/files/gumisamotogolibulumep.pdfIn PDF document text
    • https://ecoolteh.eu/galeria/file/nimudojezi.pdfIn PDF document text
    • http://full814.com/upload/files/13575303491.pdfIn PDF document text
    • https://santa.sg/images/users/00000000/files/88272128516.pdfIn PDF document text
    • https://imotrading.com/images/userfiles/xojofabusaf.pdfIn PDF document text
    • https://emartdeko.pl/galeria/file/409676039.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_off0000c56d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC56D 17484 bytes
SHA-256: 55d3a86e82b67c56684bc34547d7bc1f10cc77acf2d8dc93819ebdb2d0ea7b30
font_01_sfnt_off0000f34a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF34A 10256 bytes
SHA-256: dd3c4f3b90dfc360776700a6681a9e693ccee0b567c5c4b547a86039c283f625
font_02_sfnt_off00010a93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A93 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1