Malicious PDF — malware analysis report

Static analysis result for SHA-256 223d54742273a491…

MALICIOUS

PDF

73.3 KB Created: 2021-04-19 05:45:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 63b48737335e2f6b964665ee415a5927 SHA-1: 474041abb57a001c2bc02bc5d0fb6c39a7e9b5f5 SHA-256: 223d54742273a491f8309411ce871c9f6e5adad26ab91940cd625e7ffde41f15
126 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it is a link farm on disposable hosting. The embedded URLs and the PDF structure suggest an attempt to redirect the user to potentially malicious sites. Although no scripts were explicitly extracted, the PDF format itself can embed JavaScript for malicious purposes, and the heuristics point towards a phishing or malware distribution vector.

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 http://cicatsalud.com/html/sites/default/files/webform/604022749.pdf In PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/38059385999.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/tekuxegejarikuferibo.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/vinoku.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/6948618973.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/natogaj.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/julojulixizegusu.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/~3/6naE_Nh8_CY/uplcv?utm_term=boss+gt+1+dimensionsPDF link annotation
    • https://lib.asu.edu/system/files/webform/98562832035.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/85064040694.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/ninavixokamorul.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/5272012193.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_off0000e2e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2E8 4908 bytes
SHA-256: 7a28c382a5f7fa0793e6358f1a122ae781feaaa9dc1116da5c901465e0377a0e
font_01_sfnt_off0000f395.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF395 10576 bytes
SHA-256: 32799940c440799173d714ad585a6429facd6a51fe69c320c671187dcda1868f