Malicious PDF — malware analysis report

Static analysis result for SHA-256 749685baf40c3778…

MALICIOUS

PDF

68.3 KB Created: 2021-04-16 18:15:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: ac3ea6e1a00154f844225d3cb8d0ad76 SHA-1: 93109875dae891fbf49707f65e7f59418bc9e304 SHA-256: 749685baf40c37783c028e79ddaed2a0ca98b1972b54ad537269eef9781f54de
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable or unknown domains, suggesting a link farm or phishing lure. The document body is heavily obfuscated and contains what appears to be junk data, but the presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a deliberate attempt to create a link farm. No scripts were extracted, but the overall structure and heuristics point to a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://oaklandchildcare.org/sites/default/files/webform/subeditanutojodojewogize.pdf In PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/woluweweketasuzizolog.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/tatesejozamelifat.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/78191676466.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/tekuxegejarikuferibo.pdfIn PDF document text
    • https://www.cdcplumbing.com/sites/default/files/webform/contact-us/sawifujemenolezaf.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/53132673180.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/zuguxinukebezukul.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/zasadavatemomafupe.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/mibotemesasis.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/LPIa9PGmDLg/uplcv?utm_term=what+does+cloud+nine+meanPDF link annotation
    • https://minorsoncampus.princeton.edu/system/files/webform/wetesagepe.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/60959229638.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/68382108709.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_off0000cfc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFC5 5096 bytes
SHA-256: 84ec4453e8f0bbd795d379ede75331b2d824ff51fb9927e56462720cabb5a16d
font_01_sfnt_off0000e100.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE100 10024 bytes
SHA-256: 0ca6a430f5bb4b11931313ff9f7b884bcb52673bd3c3e6fefbdb0877be55807b