Malicious PDF — malware analysis report

Static analysis result for SHA-256 70aeb6a67f1b97b0…

MALICIOUS

PDF

68.5 KB Created: 2021-04-14 18:36:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: d5ab2230e529719d0a503a22d263f595 SHA-1: c1084205b22d8307b92620ac69db2091bc23b758 SHA-256: 70aeb6a67f1b97b00883758d1eb7f0ef6dd63f51b869eebe7096c96d15a4918b
126 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. The document body, though heavily obfuscated, contains references to 'sheet music easy' and the authoring application 'wkhtmltopdf', suggesting a lure. The presence of numerous embedded URLs, many pointing to disposable link farms, indicates an attempt to redirect the user to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to exploit users through deceptive content and link redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://natsihwa.org.au/sites/default/files/webform/17015803.pdf In PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/93477879009.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/jebumimebugamoto.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/garuwofewitenobakufenewi.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/fapulewamekunasu.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/65827293628.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/4279473489.pdfIn PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/nisegat.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/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=one+summer%2527s+day+sheet+music+easyPDF link annotation
    • https://campusrec.princeton.edu/system/files/webform/jelozubunumi.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/85064040694.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_off0000d061.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD061 5308 bytes
SHA-256: f9bdeac7bdddd5e955e21b0dc2d34cb9952f3b846ca13e0feebd4c9c08986033
font_01_sfnt_off0000e24b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE24B 10324 bytes
SHA-256: 08b360c2ad639c4c13dca401043bbbb996707c17bb9122d0d57a07d422e2aa99