Malicious PDF — malware analysis report

Static analysis result for SHA-256 c85cd9852ef371e0…

MALICIOUS

PDF

69.5 KB Created: 2021-09-17 23:56:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 575f4af0fbc4775279b30b8e94b41246 SHA-1: 3dc7a2bee86d46804b0da64936900ebf02424d0a SHA-256: c85cd9852ef371e0794ac6946a1051e303142eb597eabaa6e395915c70d30a85
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV and an ML classifier as malicious, with heuristics indicating it functions as a link farm. It contains numerous URLs pointing to disposable domains, suggesting a phishing or malware distribution scheme. The presence of embedded JavaScript, though not explicitly detailed in the provided evidence, is a common technique for exploiting PDF vulnerabilities or redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://drafthe.ru/uplcv?utm_term=my+hero+academia+s2+e16 PDF link annotation
    • http://wwsm-us.com/files/file/zakigolibokiber.pdfIn PDF document text
    • https://adikkeempat.com/contents/files/bewugosogidibe.pdfIn PDF document text
    • https://dacola.com/upload/files/buditodomimidotaladusar.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135c0e147535---bevufikozugimokoz.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/78843109739.pdfIn PDF document text
    • http://schokoladenbrunnen.de/idata/45152014684.pdfIn PDF document text
    • http://onlytech-tunisie.com/userfiles/file/6014892770.pdfIn PDF document text
    • http://cga82.com/admin/File/66129836387.pdfIn PDF document text
    • https://chief-moving.com/editor_upload/file/videmogojewosolugarar.pdfIn PDF document text
    • http://househouse.it/userfiles/files/zusekimudiguna.pdfIn PDF document text
    • https://clinicaabrahaoosta.com.br/ckfinder/userfiles/files/kikexilowopibijuxuxipoma.pdfIn PDF document text
    • http://lesmashclub.com/imgUpload/files/6672905390.pdfIn PDF document text
    • https://ce-mi.pl/uploads/userfiles/files/jumugegufifow.pdfIn PDF document text
    • https://eclearusa.com/images/file/77055265231.pdfIn PDF document text
    • http://pc580.cn/upload_fck/file/2021-9-1/20210901110259432120.pdfIn PDF document text
    • http://kientrucsangtrong.com/plus/files/fivijubikidisor.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/17024679622.pdfIn PDF document text
    • http://www.iciparis.ru/ckfinder/userfiles/files/zowamavibesijiwiduk.pdfIn PDF document text
    • http://farashimirooz.com/files/bipuvadomitixarabupufis.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132047b84ba6---wesutolivina.pdfIn PDF document text
    • http://abwgulfport.com/uploads/files/20717945056.pdfIn PDF document text
    • http://wxmx.cn/upload/ckimg/files/202109111956238658.pdfIn PDF document text
    • https://thefertilizerequipment.com/d/files/885027376.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/dejefalubinoz.pdfIn PDF document text
    • http://machin.kr/userData/board/file/14459241126.pdfIn PDF document text
    • https://ms02bet.com/contents/files/12650344584.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_off0000b07b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB07B 10832 bytes
SHA-256: 8d72940a353009e0794f0b6c4541996f38e5f9b0e06f65f9c5d1c612358e50c7
font_01_sfnt_off0000c998.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC998 15176 bytes
SHA-256: 0f338be9dd3444496318a646e3b002da84364090540d58e969793ccdadb6730f
font_02_sfnt_off0000ef26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF26 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1