Malicious PDF — malware analysis report

Static analysis result for SHA-256 85388ccc3fd46602…

MALICIOUS

PDF

89.1 KB Created: 2021-04-20 00:14:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: d83a5a4438ea84cf3ca8a03e7b2378ed SHA-1: 490afa151987933093e8f7f970aa84adb4a6eca2 SHA-256: 85388ccc3fd466025b07f47d5aec56d01884e68601ff26772468eb1dd8d6cf92
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. The document body, though heavily obfuscated, suggests a lure related to creating XML files, likely to trick users into clicking embedded links. The presence of numerous external URLs, many hosted on seemingly legitimate domains but pointing to PDF files, further supports a phishing or redirection attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://web.liderpapel.com/sites/default/files/webform/wavunivuzabanovomid.pdf In PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/72789215659.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/71048230710.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/26147793628.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/51131620028.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/gafazibo.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/16831560309.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/22206840813.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/YTWXjIUwRh0/uplcv?utm_term=como+crear+un+archivo+xml+desde+bloc+de+notasPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/43157208480.pdfIn PDF document text
    • https://umatter.princeton.edu/system/files/webform/requests/72435273025.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/kabajizonen.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_off00011f5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F5E 5352 bytes
SHA-256: 6de833bf62b05b341368205f88f89f92cb8be700d267b1604b66c065e1731d24
font_01_sfnt_off00013163.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13163 11904 bytes
SHA-256: 8cfef47ec3f0350acd545c1af5920367ab697648c1724fcdf1478cd4a0eeb081