Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5612390481367ad…

MALICIOUS

PDF

76.7 KB Created: 2021-06-01 19:54:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: e027cc8490f7d5e218e6a832c87ec67e SHA-1: ef7c88ae067dabda9a95c1c2022d07aff9716dcf SHA-256: c5612390481367ad02fac2adcec62de189a015618aa3933ae8027ea68cd89dba
186 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains a large number of external links pointing to various PDF files hosted on disposable domains, indicating a link farm designed to distribute malicious content or phish users. The document body itself is largely unreadable due to truncation and encoding, but the presence of URLs and the heuristic findings strongly suggest a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://chcial.ru/pbw?utm_term=academic+achievement+of+students+with+hearing+impairment PDF link annotation
    • https://rubuvewoxuvima.weebly.com/uploads/1/3/4/8/134873715/5971157.pdfIn PDF document text
    • https://mamudige.weebly.com/uploads/1/3/0/8/130874639/nenezifibufog.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480728/normal_60241ee696ebb.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4385620/normal_60b14d1ab2dcc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490529/normal_6033f6c921d3a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457272/normal_605d6c5a2c63a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451027/normal_6047799766c30.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370309/normal_5ff500aa83dc9.pdfIn PDF document text
    • https://sejoxamopizava.weebly.com/uploads/1/3/1/8/131858661/gadezim.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495707/normal_605231b2b9576.pdfIn PDF document text
    • https://xeruwuxopexok.weebly.com/uploads/1/3/4/4/134467304/lesipixova.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375341/normal_6069de9f174b8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4495395/normal_6001ec1d1975a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496151/normal_603c2801738bf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385009/normal_606ca15e4bbe4.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4389816/normal_60b00777082f1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403683/normal_601284ca9a466.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451971/normal_6059ed628dc11.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://tusawijer.pbworks.com/f/fisiologia_de_la_conducta_carlson_11_edicion_gratis.pdfIn PDF document text
    • http://mikabipi.pbworks.com/w/file/fetch/144432633/94739543828.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/da9a2079-51f6-4f92-bab3-e726075c6063/vabewedodaj.pdfIn PDF document text
    • http://wuwazilizos.pbworks.com/w/file/fetch/144425859/noretakikinaj.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6d0c57b2-da63-40f0-8747-e230151d2171/29693208976.pdfIn PDF document text
    • http://kipizasuzeda.pbworks.com/f/sunilituro.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/682d77aa-922f-4c23-a9ac-2dcfadb0d87e/71998367512.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_off0000ec52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC52 5680 bytes
SHA-256: dc71289cd9c93439215483c794c5d919d1dec38ce592e83ad985b462d3434d47
font_01_sfnt_off0000ff98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF98 10752 bytes
SHA-256: 2b7687c61cc6d2b7623f34dd299e8b6b4764cef71b8003e64c2a6ae7ca241838