Malicious PDF — malware analysis report

Static analysis result for SHA-256 82b6b2d534605404…

MALICIOUS

PDF

67.8 KB Created: 2021-04-08 08:32:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 24d8cd9669a51cbdc4eaffd64e8cee05 SHA-1: 303ae74c7880b23179bc3c11f3dc2b95d4b57a86 SHA-256: 82b6b2d534605404711aa4c42e4b503cd37abcc9dd78d918ec684e8db4594809
126 Risk Score

Malware Insights

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

The PDF document is identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous embedded URLs, many pointing to disposable domains or link farms, suggesting an attempt to distribute malicious content or phish for information. The document body, though heavily obfuscated, suggests a lure related to 'piano sheet music pdf free download'. The presence of external URIs and link farm heuristics strongly suggests the document's primary purpose is to redirect users to malicious sites.

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://cicatsalud.com/html/sites/default/files/webform/93477879009.pdf In PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/22435641867.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/4264017636.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/12132802610.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/88699151804.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/dufadurelabakugozuku.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/lozege.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/mibotemesasis.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/98751459569.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/90077644064.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/pagasumoxozodaxatukaliwus.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/93322629498.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=piano+sheet+music+pdf+free+downloadPDF link annotation
    • https://campusrec.princeton.edu/system/files/webform/26909318775.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_off0000ce3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE3B 5488 bytes
SHA-256: d34021294a98a16aaeb310aec8e90bc627fab6b9ffeb675225b088c99e6a9e89
font_01_sfnt_off0000e0d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D0 9732 bytes
SHA-256: 43c008bf5d323d4609c4c65a1b35b76068812bc5c003557ff66e47e697a1f29d