Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9d45d292884d096…

MALICIOUS

PDF

68.9 KB Created: 2021-04-13 14:18:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 6b06cb9bf0a0303e316f7b701fe4e686 SHA-1: 309c87e43beaacebaf3c47205038a72ab7477051 SHA-256: f9d45d292884d09695915992e7983a355645292a6c99b81250b25585f1d0f88f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains numerous embedded links, many of which are hosted on educational or organizational domains but appear to be part of a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a high likelihood of malicious intent, aiming to obscure the true destination of the links. While no scripts were explicitly extracted, the presence of external URIs and the link farm structure suggests a phishing or redirection attempt, likely to deliver a second-stage payload or lead to a credential harvesting page.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 https://ambrose.edu/sites/default/files/webform/9979090083.pdf In PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/dojoxopanikofogenag.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/38059385999.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/30150103061.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/nibobuzokojovafizuza.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/19824824677.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=the+critical+reader%253A+the+complete+guide+to+sat+reading%252C+3rd+editionPDF link annotation
    • https://lib.asu.edu/system/files/webform/liwubuwivak.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/83328436210.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/17420147243.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/86626084736.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cef6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEF6 5704 bytes
SHA-256: 72bb422e9c063c794b6dda00cb0029ac12e2b8b1b31cafe2bab4e8e52f9fcdf5
font_01_sfnt_off0000e23f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE23F 10540 bytes
SHA-256: 15acfb64e6c2d228587709d26171654bafd6b527de0a40a618c3625da32d02c2