Malicious PDF — malware analysis report

Static analysis result for SHA-256 b55bb0948dac7a99…

MALICIOUS

PDF

86.4 KB Created: 2021-09-17 07:05:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: dd2296ff88ed6947381a47d3dc379f27 SHA-1: 78ad24968b4ae8b6aec9a67eb29753ced7b17026 SHA-256: b55bb0948dac7a992e9e542834a0b91a3178808a5ae175061553f791639f0d4d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution lure, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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=words+that+start+with+k+and+end+with+r PDF link annotation
    • http://vsrru.ru/userfiles/file/8162427530.pdfIn PDF document text
    • http://gruppocaminiti.it/userfiles/files/tageviweribag.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/34118027053.pdfIn PDF document text
    • http://bahtiyardishekimi.com/fckfiles/file/tarazakonazatatokew.pdfIn PDF document text
    • http://an-ocn.ru/ckfinder/userfiles/files/tujojirixoporivumupanut.pdfIn PDF document text
    • https://asiapharma.la/files/files/4334950537.pdfIn PDF document text
    • http://www.tiande-global.com/ckfinder/userfiles/files/6537366812.pdfIn PDF document text
    • http://maynenkhipuma.vn/quangbasanpham/app/webroot/upload/image/files/34214657026.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161410d796649f---54503795905.pdfIn PDF document text
    • http://fence-alarm.com/userfiles/files/pegor.pdfIn PDF document text
    • http://shipsupply.ru/userfiles/files/zipadoboxikutasafi.pdfIn PDF document text
    • https://karolinanowak.com/userfiles/file/57159404338.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136e1bdabae9---41886340406.pdfIn PDF document text
    • http://hanyangsteel.com/files/fckeditor/file/183140222361317f05b3601.pdfIn PDF document text
    • http://hostingureitings.lv/uploads/userfiles/files/neromakofonifusenaroliw.pdfIn PDF document text
    • http://sushistoryus.com/uploads/files/jotorapetelajugizamo.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/f949ppgotcbnqtmqbkcars7987/kokabekaxo.pdfIn PDF document text
    • https://xebecdesign.com/xebec/userfiles/file/nasoxuvuxojeki.pdfIn PDF document text
    • http://guanzhuli.com/userfiles/file/23457787544.pdfIn PDF document text
    • https://www.mppoa.cloudlinesystems.com/assets/ckfinder/userfiles/files/nedikolofonazipo.pdfIn PDF document text
    • https://alcoquimicos.com/ckfinder/userfiles/files/27527425504.pdfIn PDF document text
    • http://newdimension.su/userfiles/file/8912057812.pdfIn PDF document text
    • http://dunakeszi.varosom.hu/userfiles/files/85407071711.pdfIn PDF document text
    • https://faresaldabbous.com/uploads/files/53822770359.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_off0000ed32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED32 10468 bytes
SHA-256: 24156053efabf0e50063f313f10a70cd1f284a98b439d862e2f272bd38d3c774
font_01_sfnt_off000104fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104FA 17828 bytes
SHA-256: 3b5be8087511b6ee528ecd14369a9f3021f3fa4ab4c812908e2f27b164a09632
font_02_sfnt_off00013381.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13381 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1