Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5cdad4fbf4e4422…

MALICIOUS

PDF

72.5 KB Created: 2021-09-22 12:17:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f4bc175a0038779ea110ac77245a8fc2 SHA-1: b4d44482ff3fb8166e3a30fec2e1a2fc6a714c9f SHA-256: a5cdad4fbf4e4422dda2d9fae4eab7fbb2002148e58eb328f945900e03855f0b
134 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable or unknown domains, indicating a link farm designed to obscure the final destination. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'ML_NYX_PDF_MALICIOUS' strongly suggest malicious intent. ClamAV detection further confirms its malicious nature, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.sherpachristain.org.np/ckfinder/userfiles/files/14224330872.pdf In PDF document text
    • https://tele-video.ru/upload/files/92800114927.pdfIn PDF document text
    • https://mobilieroccasion.fr/uploads/file/81313362182.pdfIn PDF document text
    • http://amandamaitland.com/images/file/2470786288.pdfIn PDF document text
    • https://lanjutpt1.com/contents/files/60855151814.pdfIn PDF document text
    • http://brezov-gaj.si/uporabnik/file/1138991040.pdfIn PDF document text
    • http://heizler.hu/files/file/tejibuliretelaxusol.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/nubejavezorebavodubewof.pdfIn PDF document text
    • http://swancentive.com/cote_dor_import/admin/ckfinder/userfiles/files/36980615648.pdfIn PDF document text
    • http://tk-weld.com/images/library/File/19031088160.pdfIn PDF document text
    • http://bigyikesmedia.com/home/xtremweb/public_html/consultinstitute/web/upload/files/88808394831.pdfIn PDF document text
    • http://ajambary.com/userfiles/file/72100740225.pdfIn PDF document text
    • http://windowsplusllc.com/ckfinder/userfiles/files/43395926034.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/punukelo.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/7d12ac5c54b6d0bba343bc9410f77e4a/moruza.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1631444351.pdfIn PDF document text
    • https://weborder.cloud/userfiles/file///16876332456.pdfIn PDF document text
    • https://nordavril.com/userfiles/file/78155090865.pdfIn PDF document text
    • http://moscowballet.ru/userfiles/file/44862368522.pdfIn PDF document text
    • http://predit.ru/admin/ckfinder/userfiles/files/80173991111.pdfIn PDF document text
    • http://ediliziaunoaventi.com/userfiles/files/72777227432.pdfIn PDF document text
    • http://gianenricofabro.com/userfiles/files/27664219756.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=colour+by+number+dragonPDF 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_off0000b9b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9B1 10616 bytes
SHA-256: 1b4d81e9ffe2aec8c00104b97c810b3ae7131f8713d9e6298b6ee5b3841732ed
font_01_sfnt_off0000d1b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1B8 16916 bytes
SHA-256: b4ed366d33cbb587cb9fe7c1fb938cb7f0786191419f4f0925347cd6fb2bff28
font_02_sfnt_off0000fcf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCF5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1