Malicious PDF — malware analysis report

Static analysis result for SHA-256 0bc725351239a61a…

MALICIOUS

PDF

79.7 KB Created: 2021-10-11 12:58:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 872d4f72ab059d10d1c3f8cfd47c2cdd SHA-1: 918c8d823bef4efffd9aaf27424f9dbf0aafe458 SHA-256: 0bc725351239a61ab71596ad4a055455aea4831f75ca0d257644cf5fb58288da
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, directing users to various unknown domains. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution scheme, likely initiated via a spearphishing attachment.

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 http://sushimura1.com/uploads/files/kigupajirinoxigutelet.pdf In PDF document text
    • http://rebeccaosborne.com/uploads/kazukir.pdfIn PDF document text
    • https://asiapharma.la/files/files/24185482312.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021091307001048.pdfIn PDF document text
    • https://gogift-it.com/userfiles/files/naxukugidiwodakudar.pdfIn PDF document text
    • https://barcelonacentromedico.es/files/galeria/files/61776398760.pdfIn PDF document text
    • http://archive-2011.humandoc.pl/attachments/file/zosotomavifobesinimevot.pdfIn PDF document text
    • https://uzmanwebci.com/calisma2/files/uploads/22533948530.pdfIn PDF document text
    • http://x04ydivan.ru/userfiles/file/64931815352.pdfIn PDF document text
    • https://callmarkinvestments.fortunekenya.com/callmark/files/desabagumijusilivifo.pdfIn PDF document text
    • http://garant-fond.ru/ckeditor/ckfinder/userfiles/Images/files/wazodolakiwi.pdfIn PDF document text
    • http://portalpr-b2b.es/img/user//file/_0711330001632726256.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/161526fbe80345---tufanufuv.pdfIn PDF document text
    • http://yyfxsw.com/upload/files/tisugixize.pdfIn PDF document text
    • https://xn--fct8ml6mwue.tw/uploads/files/64850160337.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/92564760026.pdfIn PDF document text
    • http://ecofincas.net/ckfinder/userfiles/files/desedubagirokavanun.pdfIn PDF document text
    • http://thamcohoaian.com/webroot/img/files/6837522185.pdfIn PDF document text
    • https://clubelsendero.com/img_pag/file/60521517166.pdfIn PDF document text
    • http://kaupa.cz/userfiles/file/21351125068.pdfIn PDF document text
    • http://baschin-heizung.com/meineBilderAlbertGrundschule/file/9709489912.pdfIn PDF document text
    • http://library.nesdb.go.th/ic/admin/ckfinder/userfiles/files/20757726506.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/RhDyTiV0TgQ/uplcv?utm_term=section+4.3+modern+atomic+theoryPDF 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_off0000cec8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEC8 10928 bytes
SHA-256: acee68612088160cbae220cb3068608d5c1692819718a09131adf58ac4dc62da
font_01_sfnt_off0000e7fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7FC 18904 bytes
SHA-256: 6ee28eb4aae6df6fe05dcfe757701a7fb00b63eb9f8925bc9585f03ed7bd3a73
font_02_sfnt_off00011945.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11945 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1