Malicious PDF — malware analysis report

Static analysis result for SHA-256 39f9c66e1873d89b…

MALICIOUS

PDF

85.8 KB Created: 2021-08-08 13:04:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a5091efd6826c8ae069b159fd2f8346e SHA-1: 43c8a6cf23bc8601aed78aa25d28ac10ef45536e SHA-256: 39f9c66e1873d89bb0f63ddd11cc611db667f64092f706bae42f34470ecd3e8e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm used to redirect users. The presence of external URIs and a high risk score further support its classification as a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://b2cexpressdemo.com/userfiles/file/23259343888.pdf In PDF document text
    • http://omak1968.com/clients/71178/File/vumapote.pdfIn PDF document text
    • http://namngonviet.vn/user-/files/tadedexanutaj.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/a07542fef74e6f92506bea69e51dd218/8593757214.pdfIn PDF document text
    • https://abe-rdc.com/userfiles/file/sumurigimiladulitog.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d05a9d0da3---49308738562.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a400182036---saxitas.pdfIn PDF document text
    • https://menu2uplus.com/images/file/24731345705.pdfIn PDF document text
    • http://www.retorika-zidar.si/ckfinder/ckeditor_uploaded_files/files/38683053598.pdfIn PDF document text
    • https://www.helpforbusymums.com/wp-content/plugins/super-forms/uploads/php/files/9e75663c4f9c362c5c6f63f1768dade0/22355866699.pdfIn PDF document text
    • https://balustrady-metalik.pl/files/1474340270.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609283748bf28---72569684425.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/3rcevbrc29qhma2n23dkou601l/rodovodilera.pdfIn PDF document text
    • https://graveyards-fuj.ae/userfiles/files/sejifuzawinivoredamovujo.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/xegivefoniberasalomafu.pdfIn PDF document text
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608cf9784d93c---32890823455.pdfIn PDF document text
    • http://rotang.net/userfiles/file/73266668488.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/203cac18e6aa86612f113eb3af3b3fa3/tufazixobomesozesop.pdfIn PDF document text
    • http://zxpgw.com/userfiles/file/mugitokorusot.pdfIn PDF document text
    • http://smn68.com/clients/75339/File/bikufed.pdfIn PDF document text
    • https://marathonroller.com/userfiles/files/famupotiso.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/16ak495d783ab9ta9mdiol29u0/xekirosixelofo.pdfIn PDF document text
    • http://bamila.vn/luutru/files/kapefarekor.pdfIn PDF document text
    • http://lucchetta.net/userfiles/files/66720700577.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/67393283036.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=what+literary+devices+are+used+in+the+outsidersPDF 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_off0000ea88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA88 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001029a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1029A 16932 bytes
SHA-256: cbd5e18cc1cbef4d16b4a16b6d5a78d16b3f827d47cbaac60934accfc39ea3d1
font_02_sfnt_off00012f13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F13 10740 bytes
SHA-256: 3f67ad6bc8d12e3263c71fff760de8d1b19de83f9aa21b11e3f25c62265e3153