Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bd88b11115e06e3…

MALICIOUS

PDF

76.6 KB Created: 2021-03-20 20:42:07 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: a262bddbf22e68a65b75562957358752 SHA-1: ff443c52c2e205bfaa1f4d8f0b964c5110d7032f SHA-256: 4bd88b11115e06e3f191007c85de7e2a96934e01d17c265906a8f7dae165b515
166 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and ML classifier indicated a high probability of maliciousness. Heuristics identified suspicious links, including invisible ones pointing to domains like 'securityofusersdevicesonline.site', suggesting a phishing or malware distribution lure. The document's structure and embedded URLs indicate an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Image-heavy PDF with invisible link to suspicious domain high PDF_SUSPICIOUS_LINK_LURE
    PDF is a small image-heavy lure with invisible link annotations that send the user to a suspicious high-risk-domain URI. This matches credential-phishing carriers where the visible document is only a prompt and the real collection flow happens on the linked website.
  • 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://bologen.ru/123?utm_term=android+bypass+ssl+certificate+pinning PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4458421/normal_5fe85543d2514.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379626/normal_60513fe84fcb1.pdfIn PDF document text
    • https://cdn.sqhk.co/rizikodeni/ZdEjbcc/75344931307.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4371814/normal_5ff2935f9e7bc.pdfIn PDF document text
    • https://cdn.sqhk.co/fomeluxilim/fijHheV/16763217095.pdfIn PDF document text
    • https://cdn.sqhk.co/talexadu/td9ic1p/xitomapewofajad.pdfIn PDF document text
    • http://securityofusersdevicesonline.site/15912199021medyk.pdfIn PDF document text
    • http://iranomics.com/ned_s_declassified_school_survival_guide_movie989jl.pdfIn PDF document text
    • http://evromotors.net/where_to_donate_gently_used_childrens_clothesx7swi.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4365649/normal_5fe60053a3e2f.pdfIn PDF document text
    • https://cdn.sqhk.co/zovaratigu/MIhgxgd/doluzomikeji.pdfIn PDF document text
    • http://begdas.fun/disazamazildwg1.pdfIn PDF document text
    • http://topcabinets.xyz/tom_clancy_without_remorse_movie_trailerjza5x.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408992/normal_5fc7a483deef2.pdfIn PDF document text
    • https://cdn.sqhk.co/bunigenozav/pEbQFhe/lowitu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/rerinago/xinukaruxazazuforesijaz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/de6703b3-23af-4059-86d1-5271a5dab603/grammar_english_checker_software.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3dae71fa-9a93-428c-89ce-a505092d6bc6/48818168019.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ecb281a4-7a82-4b55-82b3-ba0df4988b97/85864057263.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/59f69e6f-b7f2-4f72-96ae-a2716893af01/tavelimu.pdfIn PDF document text
    • https://s3.amazonaws.com/wudibirewuduto/87876404019.pdfIn PDF document text
    • https://s3.amazonaws.com/naxizugenabi/private_candidate_form_four_results_2017.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_off0000ead8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD8 5552 bytes
SHA-256: f278e76c187844d8594225b98f6b2f6a10f7adf1690e245a352ead3e185b25ef
font_01_sfnt_off0000fdd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDD0 11448 bytes
SHA-256: d0e8f7d9a1837f320a8017c8d3642fe357d5e8d6864f21607f14df5585d9ed5f