Malicious PDF — malware analysis report

Static analysis result for SHA-256 88b4f8348cec7c4e…

MALICIOUS

PDF

95.8 KB Created: 2021-09-18 05:20:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 809e0a5e23a9f87ef12566e4e2caa8c1 SHA-1: 15992973e462dd0c5d34dce013a8c842bcd7b860 SHA-256: 88b4f8348cec7c4ecdb469bcdd3e86343205cb9641c130b6259b6e96ab5f69ad
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to disposable domains, and one heuristic identified it as a link farm. While no scripts were explicitly extracted, the nature of the embedded URLs and the link farm heuristic suggest an attempt to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

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://iuoshili.com/upload/users/files/zelezuvurugibura.pdf In PDF document text
    • https://ymy-tea.tw/upload/files/98848645056.pdfIn PDF document text
    • https://newcar-rental.com/uploads/files/202109140637048470.pdfIn PDF document text
    • http://autovoda.ru/upload/files/41965215098.pdfIn PDF document text
    • https://bvphcn.bdata.vn/upload/files/74218627081.pdfIn PDF document text
    • http://ateliergermain.org/sites/default/files/file/lewuperukowokafubeme.pdfIn PDF document text
    • https://marwaservicecenter.com/nbloom/fckuploads/file/pezeworikuligafuf.pdfIn PDF document text
    • https://santevita-bg.com/ckfinder/userfiles/files/6618845956.pdfIn PDF document text
    • http://khangvietdn.com/uploads/file/15282915738.pdfIn PDF document text
    • https://colakcivi.com/userfiles/file/38187873512.pdfIn PDF document text
    • http://nattuvaartha.com/assets/ckfinder/core/connector/php/uploads/files/68118150550.pdfIn PDF document text
    • https://partroyfuneralhome.com/partroy/assets/file/26023938229.pdfIn PDF document text
    • http://happyhanool.com/ckupload/files/27196852978.pdfIn PDF document text
    • http://hausdergesundheit.net/userfiles/files/49991661401.pdfIn PDF document text
    • https://www.akilciilacdernegi.com/ckfinder/userfiles/files/6486306716.pdfIn PDF document text
    • http://ttlh.vn/storage/ckfinder/files/11680762080.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/be96492d7b3e39d3bcdc2aff5d5830ba/95239325677.pdfIn PDF document text
    • https://www.smartfutureexpo.com/ckfinder/userfiles/files/54742051815.pdfIn PDF document text
    • https://spyboarcams.com/files/34557845328.pdfIn PDF document text
    • http://photonart.nl/phpcmsys/file/57592410790.pdfIn PDF document text
    • http://taiwan-casters.com/userfiles/file/wozowepagukugala.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/26919330690.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/sorurefibafisotab.pdfIn PDF document text
    • https://renetravel.ro/images/files/49018617541.pdfIn PDF document text
    • http://xn--or3bo5mvlb.com/data/editor/file/9769462439.pdfIn PDF document text
    • https://butyfarm.mm520.net/userfiles/files/bunagapekowewuwij.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=the+dead+charlie+higson+pdfPDF 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_off00011279.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11279 17932 bytes
SHA-256: 2563157e8443fed421c51d3336997655698c8dcc47493568e5c67b963edbe388
font_01_sfnt_off000140fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015911.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15911 10764 bytes
SHA-256: c774c010f3b354726ebad5332be554d2f5e45948eb78b2dc638f7a5ae532f257