Malicious PDF — malware analysis report

Static analysis result for SHA-256 86a84d8b04915b41…

MALICIOUS

PDF

82.5 KB Created: 2021-09-18 14:43:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9678cbb606cf8c06cff1014a2bda0ef4 SHA-1: 000701947bbbb73b1a0759997bb079db7f5c1153 SHA-256: 86a84d8b04915b411852cede0821ebd98dc800d52613a3f72b603f0ebfb2682d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate it functions as a link farm on disposable hosting, with numerous embedded URLs pointing to PDF files. While no scripts were explicitly extracted, the PDF format often utilizes JavaScript for malicious actions, and the overall structure suggests an attempt to lure users to external resources, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://londonjip.com/userData/board/file/83155250659.pdf In PDF document text
    • http://www.icf-plant.com/files/file/reluxido.pdfIn PDF document text
    • https://designclarf.it/file/24557728163.pdfIn PDF document text
    • http://santeh.md/img/files/81333604103.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395a9a98264---7945555925.pdfIn PDF document text
    • https://pakianco.ir/data/image/uploads/news/files/tirizopagefepesiluro.pdfIn PDF document text
    • https://masterjobintl.com/ckfinder/userfiles/files/mejoparidogujumuf.pdfIn PDF document text
    • http://zezoalza.com/ckupload/files/kesuk.pdfIn PDF document text
    • http://nokianhakkablue.ru/ckfinder/userfiles/files/3480991799.pdfIn PDF document text
    • http://nbc.com.vn/ckfinder/userfiles/files/zasegejiduzinedegegesuwe.pdfIn PDF document text
    • http://predit.ru/admin/ckfinder/userfiles/files/31119500307.pdfIn PDF document text
    • http://studioarclab.eu/userfiles/files/pepelunedozajitonawozeno.pdfIn PDF document text
    • http://eatatrudy.com/uploads/files/dozitam.pdfIn PDF document text
    • https://weddingitaly.jp/images/file/duxofewiredubumaj.pdfIn PDF document text
    • http://immobilieninvestors.eu/userfiles/file/rozokowupugefepigubipi.pdfIn PDF document text
    • http://studiotecnicofrisoli.com/userfiles/files/javobivaregujugurepine.pdfIn PDF document text
    • http://mcdanielz.eu/files/file/71940547992.pdfIn PDF document text
    • https://www.terraton.com.my/ckfinder/userfiles/files/33133767915.pdfIn PDF document text
    • https://aarushimukhwas.idealviews.com/userfiles/files/87076868014.pdfIn PDF document text
    • https://heks-tech.com/app/webroot/userfiles/files/50379636680.pdfIn PDF document text
    • https://hatinhjobs.com/upload/files/jesorefegumafaloj.pdfIn PDF document text
    • https://cingenito.ca/upload/editor/file/82590642638.pdfIn PDF document text
    • http://learnersdigest.org/userfiles/file/57532829806.pdfIn PDF document text
    • http://xfswchem.com/upload/files/48845244562.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/jajugexemudefevimefoguzir.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=proxy+setting+in+uc+browser+androidPDF 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_off0000d9f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F6 11040 bytes
SHA-256: 5ae9734592b620abb62f68a9689287d03e99b87a9ea7a1546d51536fea0591ba
font_01_sfnt_off0000f3bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010bcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BCF 18476 bytes
SHA-256: 66b416348a02ed43145a3256a354fcfc694826015711035aebf1b0a71a832b0c