Malicious PDF — malware analysis report

Static analysis result for SHA-256 66c71ff1d8d0261d…

MALICIOUS

PDF

72.2 KB Created: 2021-09-16 12:06:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b4b09c45d09514795a569bdd9a859ec1 SHA-1: 05d25dfa250f3edbff29d9dcbdbbffd5a49a1664 SHA-256: 66c71ff1d8d0261d49c8c1d4c1417bb8c0bad797efbd79d3308dd0790c6d08b6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous external URLs, many hosted on compromised or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating the document's primary purpose is to host these deceptive links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://coretry.ru/uplcv?utm_term=cantata+147+bach+partitura+piano+pdf
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/5097145870.pdf
    • http://imailbox.nl/images/uploadedimages/file/9279373220.pdf
    • http://xn--e42bt3l.net/upfile/files/bunelevoronaxe.pdf
    • http://ilyxrace.com/userfiles/files/15353475144.pdf
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161314bd0b2125---dadikigewoviroletoriges.pdf
    • http://designbyjoseph.com/uploads/File/50777537929.pdf
    • https://giraffeng.net/infodaily/gen-ckfinder/userfiles/files/fevunidal.pdf
    • http://thegioixedap.net/upload/files/rakuwivukoxukebef.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/h7erghssafudbhq7lik1q4vjr2/34107895277.pdf
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/10147323382.pdf
    • http://cegled.varosom.hu/userfiles/files/donozedaxozun.pdf
    • http://naoshima-habitant.com/images/blog/file/lezonowududitofulu.pdf
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/6bbfedcaac5cf012a65639bbfff48772/zijamedoxen.pdf
    • http://kondicionery-krasnogorsk.ru/upload_picture/file/20791801177.pdf
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614112df2bb09---puzufibasefowogajirakuze.pdf
    • http://scandinavia-ex.com/images/blog/file/49681899663.pdf
    • http://veoguidecostarica.com/ci/userfiles/files/marugujixidim.pdf
    • https://bocrangsuthammy.vn/upload/files/gonekakorejoxenakafater.pdf
    • http://vanhacollection.com/images/files/11324238155.pdf
    • https://sabunwangi.com/contents/files/favonetomabogit.pdf
    • http://sorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vodiwarikusapaputufa.pdf
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/1613604ab47a99---86708575107.pdf
    • https://www.domosystem.gr/ckfinder/userfiles/files/vexodapidarivofawokam.pdf
    • http://888spirits.com/userfiles/file/duxesufiraziv.pdf
    • https://dampinggame.com/calisma2/files/uploads/3151105920.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b6df.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB6DF 16792 bytes
font_01_sfnt_off0000cef6.bin
31a566a8dfc8d5adbe1b21e4174e7972f5305486fe0f4287a969a65f758dad7f
pdf-font-stream PDF embedded font (sfnt) at offset 0xCEF6 10820 bytes
font_02_sfnt_off0000e7bc.bin
7960a186a33bea23799e2db2681510119407c0caca613d496982002f1d4f5a44
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7BC 16488 bytes