Malicious PDF — malware analysis report

Static analysis result for SHA-256 557418e3dde2c7fb…

MALICIOUS

PDF

69.9 KB Created: 2021-04-20 20:32:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 703f3ea8ba2a06599619f8ddc0b32a11 SHA-1: d3034824c5ba1672d9e2dae7d14e306143307407 SHA-256: 557418e3dde2c7fbfe278d8e305f95f5e44d9707edee44224596f7956ef263d4
126 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous embedded URLs, many of which are hosted on seemingly legitimate domains but are likely part of a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests a deliberate attempt to obscure the final destination. While no scripts were explicitly extracted, the presence of external URIs and the overall structure point towards a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.guninetwork.org/system/files/webform/heirri_proposals/44437875789.pdf In PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/bekam.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/3018222411.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/sakobonomoduriv.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/49101071505.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/89533113822.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/22559513310.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/21030689395.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/fajabenofedutetigolexid.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/30199048500.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/12404161593.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/zuguxinukebezukul.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/40110328039.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/nufideleze.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/FevRqgeaUVY/uplcv?utm_term=cyberpunk+2077+character+creation+male+redditPDF link annotation
    • https://community.princeton.edu/system/files/webform/22535495660.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/sukazejaso.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/63066688876.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_off0000d4b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4B1 5700 bytes
SHA-256: cb3ddaa9388f4891edbc313982dacb077c98ebe2ace50d050fa8bc2640e7549e
font_01_sfnt_off0000e7f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F4 10116 bytes
SHA-256: e8397401f4c1c643c4679feedef460ba5607606712ffdd8df1d5b5c2103ba29a