Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c3fc31108eb21e7…

MALICIOUS

PDF

79.6 KB Created: 2021-09-16 17:59:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 1adcd7b04057a1af5e2d564d8590016d SHA-1: b909e65de9ef896a785f81e656461a6b05a9aff6 SHA-256: 7c3fc31108eb21e7234f7c5079cc47ba29586ef1c9adb4d6d5b951d0d802f393
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting it functions as a link farm to distribute malicious content or phish users. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this, indicating a tactic to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://hanart21.com/files/userfiles/file/31593554863.pdf In PDF document text
    • https://siroyensao.com/upload/files/vuvagumugovulobixiw.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/465811e63ecd6a55c890244b97e2dd8c/64013078425.pdfIn PDF document text
    • http://patriabrno.cz/userfiles/files/wuzuvi.pdfIn PDF document text
    • https://thietbixaydungcantho.com/canthomobile2/public/images/sanpham/files/91131968389.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f15a19190c---97465330765.pdfIn PDF document text
    • http://aibasylhet.edu.bd/app/webroot/ckfinder/userfiles/files/zaxapunojuwezifapelokife.pdfIn PDF document text
    • https://classconnbio.com/img-jacson/files/zezuneleruz.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dcc323265e---20908447177.pdfIn PDF document text
    • http://hqshop24.com/userfiles/file/79341484758.pdfIn PDF document text
    • http://aibasavar.edu.bd/app/webroot/ckfinder/userfiles/files/40064035598.pdfIn PDF document text
    • http://quiltingacademy.com/fckeditor/userfiles/file/96011305.pdfIn PDF document text
    • http://bekkercoon.ru/ckfinder/userfiles/files/gapawo.pdfIn PDF document text
    • http://datavincity.com/uploads/ckfinder/files/35203169000.pdfIn PDF document text
    • http://krukaiart.com/userfiles/files/jibulow.pdfIn PDF document text
    • http://dhleisure.com/ckupload/files/jedilez.pdfIn PDF document text
    • http://www.oiseaubleu-promo.fr/userfiles/file/92652252066.pdfIn PDF document text
    • http://strategie-online.net/catalogue_dynamique/file/38772372473.pdfIn PDF document text
    • http://tainanrup.longi.tw/uploadfiles/files/20210916_060954_7277.pdfIn PDF document text
    • http://emilymillerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gejekenawalunafunagirijij.pdfIn PDF document text
    • http://daedukgs.com/admin/fckeditor/data/file/20210904142047.pdfIn PDF document text
    • https://goodline.by/userfiles/file/12782354849.pdfIn PDF document text
    • https://pima-alarms.net/slicice/file/78171256968.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=windows+365+student+loginPDF 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_off0000d19f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD19F 18156 bytes
SHA-256: f6d7a293c98e3687ac2439e803bab9dbf833660e4a81cd10d8788c965d40bca0
font_01_sfnt_off0001005d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1005D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011874.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11874 10812 bytes
SHA-256: 94b179626b3f6921e2674e606e89581583353d8dfb56a98329cbf0423fc20258