Malicious PDF — malware analysis report

Static analysis result for SHA-256 aed3523463ae5af8…

MALICIOUS

PDF

75.0 KB Created: 2021-10-02 13:34:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 32f0907bb334405de2f5433ecb118ba0 SHA-1: e68bc1fb0ac0469211d0187aeb2bb87d7e15d9b7 SHA-256: aed3523463ae5af8dcc63f4d4afcf69b9d643a9973ffe0547d494689a20bdd6a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, with one specifically noted as part of a link farm on disposable hosting, suggesting a phishing or redirection scheme. Although no scripts were explicitly extracted, the PDF structure and the presence of many external links point towards an attack pattern involving user redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://krisoc.ru/uplcv?utm_term=this+is+a+verb+that+conveys+action+that+has+an+object PDF link annotation
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/161343095c3a32---tavajo.pdfIn PDF document text
    • http://lechioutdoor.com/userfiles/file/47446346892.pdfIn PDF document text
    • http://gonganmi.com/userfiles/file/29222821138.pdfIn PDF document text
    • http://hodinovysoused.cz/upload/file/70220259483.pdfIn PDF document text
    • http://cold.lt/userfiles/file/tebunipowelasazeniru.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/gujopidakenaru.pdfIn PDF document text
    • http://hoteldanang.com/uploads/images/files/80856131547.pdfIn PDF document text
    • https://europacreativaeuskadi.eu/files/galeria/files/siwowogulixalotuporisu.pdfIn PDF document text
    • http://bigcool.net/webroot/img/files/tisudopidebijozotexamusej.pdfIn PDF document text
    • https://gitedu.in/ckfinder/userfiles/files/nozorekosiguz.pdfIn PDF document text
    • http://meghdoothsuzuki.com/uploads/fuwux.pdfIn PDF document text
    • http://lakesnwoodskerala.com/uploads/file/97875070611.pdfIn PDF document text
    • http://humanlitech.com/files/files/2262435610.pdfIn PDF document text
    • https://pet-fashion.ro/mm/file/3789464451.pdfIn PDF document text
    • http://zs-oilfieldequip.ru/d/files/mewaxipifewibaninuvel.pdfIn PDF document text
    • https://dnsbp.com/all4help/fckuserfiles/file/zovojefuwolozot.pdfIn PDF document text
    • http://zxpgw.com/userfiles/file/86767290409.pdfIn PDF document text
    • http://kqcme.yiaiwang.com.cn/upload/files/fowejodomo.pdfIn PDF document text
    • http://lysfyyy.com/upload/files/7099276810.pdfIn PDF document text
    • http://mprime.net/ckfinder/userfiles/files/83544860926.pdfIn PDF document text
    • https://accu-split.com/userfiles/files/taxosukasova.pdfIn PDF document text
    • https://net-mex.hu/ckfinder/userfiles/files/jufoviloraxo.pdfIn PDF document text
    • http://zimmerei-possert.at/26046282467.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_off0000bf4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF4E 10692 bytes
SHA-256: 89bc02a067afbb358966876c95fc6ecea825e96e8cdf059821d9bc27fa679429
font_01_sfnt_off0000d7da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000efec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFEC 17648 bytes
SHA-256: 23f7221fcf9a08e4f0d7b03c7c76a1e206d510a0ef76c1098f3551f9861756c2