Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f106f673769be50…

MALICIOUS

PDF

82.8 KB Created: 2021-08-29 09:28:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 3b1d98e29e88ed3548ee37f1ac9a194b SHA-1: 91ab17aa3b71c3f177746f8ab377c87162752df6 SHA-256: 8f106f673769be50a947b4e4cb1680eb035a3a0fc85ac84104f96a6c04557df8
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to compromised CMS upload directories, suggesting it functions as a link farm to distribute phishing content or further malware. The presence of external URI heuristics and the compromised CMS upload link farm heuristic strongly support this attack pattern.

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://philabc.ru/uplcv?utm_term=graphics+card+black+friday PDF link annotation
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084922ab4323---54843624490.pdfIn PDF document text
    • https://mangonebike.com/uploads/file/27892304156.pdfIn PDF document text
    • http://spiregene.com/image/files/20210821_094707.pdfIn PDF document text
    • http://zjbfjt.com/upload/files/50275308789.pdfIn PDF document text
    • https://promise-land.com/upload/file/26378485512.pdfIn PDF document text
    • http://andersonlawdecorah.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/54965414425.pdfIn PDF document text
    • http://lawrence-spruill.com/clients/42275/File/13227253942.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/19ff6b7c20783229ad8fa59281ab165b/jixabatosuzufonumuxidetiw.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/1eb83c39359c20aa52370cb640f04b55/ninulud.pdfIn PDF document text
    • http://cycling-software.com/files/file/meneselikakabiv.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/69af05b1bf744a7a55a50a7c1b24cb4b/19430872127.pdfIn PDF document text
    • https://economiadecomunion.com/ckfinder/userfiles/files/nutibovuladewivodebafot.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/160907e892ef65---bogunowifusuladavogawa.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/160766d17432a8---jedebozapomeva.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160856247a2fb1---86327504056.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/92eafb75295bf71bd7e6f9cac3f25ade/99764476136.pdfIn PDF document text
    • https://supportsystemsvainc.com/home/ssvi/public_html/ckfinder/userfiles/files/jibexomuxewapimugoma.pdfIn PDF document text
    • http://szentistvanpatika.hu/upload/file/funupafoda.pdfIn PDF document text
    • http://air-ned.com/uploads/files/79005121331.pdfIn PDF document text
    • http://ed-web.cz/userfilesfile/papaneluri.pdfIn PDF document text
    • https://dlt-nkp.com/fileupload/file/66971216671.pdfIn PDF document text
    • http://cateringkieuan.com/uploads/userfiles/file/43176962040.pdfIn PDF document text
    • https://asiahijau.com/contents//files/95910552165.pdfIn PDF document text
    • https://thuaphatlaihoanghuy.com/uploads/files/26215721101.pdfIn PDF document text
    • http://meteosputnik.ru/userfiles/file/36281344434.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_off0000df6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF6F 10648 bytes
SHA-256: b57064c9cd31e6136e6f38577bb042e27dea55781954b4f68622abfb521892a9
font_01_sfnt_off0000f7b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010fc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FC6 17748 bytes
SHA-256: f70ff49c92b90d5773651f7580cddc378eeb65ce0e2f779416b93aa3405de8ca