Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b885a14b1d6e6a3…

MALICIOUS

PDF

67.5 KB Created: 2021-04-10 10:57:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: eb116d33e3360b1bee761c8cfa8c5025 SHA-1: 41f3ca2273dd98f888e26b71e5834e1f00e6d95b SHA-256: 4b885a14b1d6e6a34ba81bbdb39cd535e31a3d85390f302396f1fa366ecbe348
126 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, embedding a large number of external URIs, many of which point to potentially disposable domains. While no scripts were explicitly extracted, the presence of numerous embedded URLs suggests an attempt to redirect users to malicious sites, likely for phishing or malware delivery.

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 https://www.a1touchsolution.nl/sites/default/files/wozupidojenebimovom.pdf In PDF document text
    • https://architecturaldesigninc.com/sites/default/files/36110977311.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/dagen.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/42282539280.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/basolidigululaba.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/jedirokadezat.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/falaburisidibiwad.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/bekam.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/mogewewe.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/gafazibo.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/37570077738.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/5308316073.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/YTWXjIUwRh0/uplcv?utm_term=counterfactuals+and+causal+inferencePDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/21250884575.pdfIn PDF document text
    • https://campusrec.princeton.edu/system/files/webform/47045932069.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/46273532178.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/wetesagepe.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_off0000ce43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE43 4920 bytes
SHA-256: 9dfa58caf0a7a26c3c14135684741a5ff34420423574f1f32859bf8e08248710
font_01_sfnt_off0000df03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF03 9936 bytes
SHA-256: 46adecec614fa1a082df6c1d150c5d7ebea4e95dce0f27306b4abc3f94459873