Malicious PDF — malware analysis report

Static analysis result for SHA-256 a12a689a0d369e7f…

MALICIOUS

PDF

80.4 KB Created: 2021-09-17 18:26:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d59051983182c4250bec6d96e8c9dfad SHA-1: 342aad9eb0a7af8a0c1e285b28b2cbf2b3a40674 SHA-256: a12a689a0d369e7f380480ca488bdb6fb1188c7e0ce5b946c15d3024ba4f47da
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. It contains a large number of embedded URLs pointing to various domains, suggesting a link farm or phishing campaign. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically highlights the nature of these links, indicating they are likely used for SEO manipulation or to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://nomylo.ru/uplcv?utm_term=bloons+tower+defense+5+online+free PDF link annotation
    • https://onhimalayas.com/ckfinder/userfiles/files/toleter.pdfIn PDF document text
    • https://dascalita.ro/app/webroot/files/userfiles/files/86201666584.pdfIn PDF document text
    • http://desushibar.com/userfiles/file/fopixopipewotefi.pdfIn PDF document text
    • http://gesgo.de/userfiles/file/76966195943.pdfIn PDF document text
    • https://indianhairtransplant.com/ckfinder/userfiles/files/vuxokizenejosaw.pdfIn PDF document text
    • https://svetplus.com/userfiles/files/dowapitudupudipevo.pdfIn PDF document text
    • http://augustaelectricalwork.com/editorData/file/5786314729.pdfIn PDF document text
    • http://gz-theoutfit.com/UploadFiles/FCKeditor/20210908122319.pdfIn PDF document text
    • https://www.piramideidiomas.com/ckfinder/userfiles/files/83312755258.pdfIn PDF document text
    • http://skupka54.ru/upload/m/fevixilafakedunoz.pdfIn PDF document text
    • https://alpinashop.rudy-ra.com/files/69002178901.pdfIn PDF document text
    • http://severstroysnab.ru/userfiles/file/76839829910.pdfIn PDF document text
    • http://bdsps.org/slbdavbatala/userfiles/file/mulixazur.pdfIn PDF document text
    • http://mstreatmentadvances.com/userfiles/files/padugogatiripox.pdfIn PDF document text
    • https://happyfun.tw/uploads/files/202109071759253737.pdfIn PDF document text
    • http://dptour.net/bot/ckfinder/uf/files/dejekewuvufotofuwonuj.pdfIn PDF document text
    • https://kalyna.ua/sites/default/files/userfiles/file/12920584023.pdfIn PDF document text
    • http://pastoret.it/userfiles/files/70522695016.pdfIn PDF document text
    • http://cosmikkino.ru/sadm_files/8913049753.pdfIn PDF document text
    • http://studiomanzella.com/userfiles/files/33189884317.pdfIn PDF document text
    • http://mya1fc.com/files/ckuploads/files/dusabegilonafiwabel.pdfIn PDF document text
    • https://festival-bg.com/media/ckuploads/files/kujadudewazarasarebotofe.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_off0000d668.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD668 17480 bytes
SHA-256: 9364adf5fc23037aaf8e1267da8fd2cd8779b432e71ad053f01cb280bee2d3ed
font_01_sfnt_off000103eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103EB 10456 bytes
SHA-256: c156b7aceeaae4e465c1b222621775cc09ca202f967094b4d2a4aa035b8dc0c6
font_02_sfnt_off00011be5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BE5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1