Malicious PDF — malware analysis report

Static analysis result for SHA-256 7539bc6fda52b40b…

MALICIOUS

PDF

73.3 KB Created: 2021-09-19 10:20:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 5bf2a918a7c68d8fa69c918420b75f41 SHA-1: 1287ef02f4aaf4558c49b27ff05a4ebed55f6b85 SHA-256: 7539bc6fda52b40b19e0fd0d768c89d18c0652760b17b174817996075580210f
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to disposable hosting or compromised CMS upload directories, suggesting it functions as a link farm for phishing or malware distribution. The presence of these links aligns with the Spearphishing Attachment technique, as the PDF itself is likely delivered via email.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://pistant.ru/uplcv?utm_term=ultimate+spider+man+nds+rom PDF link annotation
    • https://srmhomes.com/images/bulk_images/files/lewerosawosom.pdfIn PDF document text
    • https://mahae.hu/files/files/zapusutopagukatijoxosu.pdfIn PDF document text
    • http://radio6deenero.com/uploaded/files/33241758761.pdfIn PDF document text
    • http://0-50.ru/userfiles/file/poxizuf.pdfIn PDF document text
    • https://ymvii.com/admin/upload/files/xijibogo.pdfIn PDF document text
    • https://goldengatetaichiqigong.com/userfiles/file/ludovafetoraxoku.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/aa0561c6a3cade22491c8364739d4c37/7185246113.pdfIn PDF document text
    • http://sportschoolindex.nl/images/uploads/gikivokozazoj.pdfIn PDF document text
    • http://talani.nl/userfiles/image/file/39207156271.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144b5788c82d---keserito.pdfIn PDF document text
    • http://kalkulacka-hypo.cz/userfiles/files/xuzasapam.pdfIn PDF document text
    • http://likuidart.com/files/ckeditor/files/90189696602.pdfIn PDF document text
    • https://aynadakikemalizm.com/resimler/files/15557412480.pdfIn PDF document text
    • http://wimborst-ceramics.nl/public/view/upload/fckeditor_images/file/jusubixijibamer.pdfIn PDF document text
    • http://tramtronbetong.com/uploads/userfiles/file/74077974450.pdfIn PDF document text
    • http://gtlitalia.com/userfiles/files/56730735851.pdfIn PDF document text
    • http://vititanon.com/user_img/files/xumanutusemutumad.pdfIn PDF document text
    • https://genegurumiraclehealer.com/userfiles/file/vubekenafef.pdfIn PDF document text
    • http://cuakeobinhduong.com/upload/files/vixixemonifigamoxinukodib.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/d89d0160acfa82aefb31ae6f0798cd50/lomijod.pdfIn PDF document text
    • http://gjbbang.com/userData/board/file/22372027678.pdfIn PDF document text
    • http://hk-sai.com/ckfinder/userfiles/files/25851108328.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_off0000ba71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA71 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d283.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD283 17508 bytes
SHA-256: 70e6fc923bd9d87d99842bbb524d47330af7e0aa15ac35ec7e60f82930b491c8
font_02_sfnt_off00010027.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10027 10560 bytes
SHA-256: 896df1b38fe3c88bf3caa500feb7489f0f2902deb4a3fbc2c645515aca140405