Malicious PDF — malware analysis report

Static analysis result for SHA-256 4723938bd73a1d87…

MALICIOUS

PDF

83.2 KB Created: 2021-09-14 03:14:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2f87ab925f264675c0ce0f0cdcf3fbb0 SHA-1: dc9a65fefbc4cd432ce7cdf1ee32f192e603d30f SHA-256: 4723938bd73a1d87abeef5216c3e5ab53cdd84f5c7c35f687de0338ad0ad34d3
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. It contains numerous embedded URLs, many of which point to other PDF files, suggesting a link farm designed to distribute malicious content or phish users. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a structure aimed at obscuring the true destination or purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://sammycar.ch/sammy/sites/default/sammyfiles/newsletterfile/bunij.pdf In PDF document text
    • http://ural-resyrs.ru/data/file/ketasefinisigugevodibisef.pdfIn PDF document text
    • https://perfectsextherapy.com/public_html/userfiles/file/48255396644.pdfIn PDF document text
    • http://diakmelo.hu/ckfinder/userfiles/files/20478746098.pdfIn PDF document text
    • http://brenna-ski.pl/userfiles/file/6177455361.pdfIn PDF document text
    • http://lobanowscy.pl/userfiles/file/188360260.pdfIn PDF document text
    • https://egc.ecrom.work/syo/files/patumugasid.pdfIn PDF document text
    • http://ekhoron21.mn/uploads/files/49440623468.pdfIn PDF document text
    • http://kartinatv.org/uploads/files/xajuxulul.pdfIn PDF document text
    • http://ubytovani-budejovice.cz/picture/vtextu/file/54961548176.pdfIn PDF document text
    • http://ilovehikari.com/uploads/files/9973498065.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/161366a3ba36fd---zarukevudowivilufitatik.pdfIn PDF document text
    • http://chikatere.com/Upload/files/merateragugijeravemis.pdfIn PDF document text
    • http://hemeringen.de/ckeditor_ablage/userfiles/files/fimojazen.pdfIn PDF document text
    • http://ambvet-trefontane.eu/userfiles/files/sozimuzepapisagasanafolip.pdfIn PDF document text
    • https://garraldaarquitectura.com/garralda_userfiles/files/58384863650.pdfIn PDF document text
    • http://www.ecrivains-consult.fr/easyonline/ckfinder/userfiles/files/zejoguxaduvagaf.pdfIn PDF document text
    • https://thietbivesinhanhhuy.com/asset/files/40598147167.pdfIn PDF document text
    • http://www.themixchange.com/userfiles/files/vinusu.pdfIn PDF document text
    • http://zlhk.ru/upload_picture/file/90021983472.pdfIn PDF document text
    • http://integrotech.eu/zdjecia/file/97539150682.pdfIn PDF document text
    • https://derechosenred.org/aym_image/files/votovatuxiguwofosavop.pdfIn PDF document text
    • https://demo-calson.garment-pro.com/ckfinder/userfiles/files/2162477618.pdfIn PDF document text
    • http://the100voicesofgospel.de/fichiers/newsletter/file/moxoz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=boruto+naruto+next+generation+181PDF 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_off0000da59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA59 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f270.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF270 10584 bytes
SHA-256: dbec4dd9909f0c6a8fbd481b5319cef4f6a903623a4b95ba954ec48729a101de
font_02_sfnt_off00010ad2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD2 19764 bytes
SHA-256: c207853ec125cb0627533519903647e9ec4284f597bf7b2cf1c34e9003ba7bfa