Malicious PDF — malware analysis report

Static analysis result for SHA-256 d9aa15433886e69b…

MALICIOUS

PDF

75.6 KB Created: 2021-06-08 23:32:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 91491135b14263ff2b423c59e4e18fe9 SHA-1: a80953b4703cc4897651911b490ddeed59967323 SHA-256: d9aa15433886e69b30ed8a41528a54d60e223a837a8875200b017a1cf59b0046
186 Risk Score

Malware Insights

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

This PDF sample was flagged by multiple heuristics as a link farm, containing numerous external links to various domains. The presence of a link to 'chcial.ru' with a 'tubidy engine search music download' UTM term suggests a potential lure for users seeking content, which could lead to phishing or malware. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to distributing further malicious content or phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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=tubidy+engine+search+music+download PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4369764/normal_5fc9b49ac5c60.pdfIn PDF document text
    • https://simipupipez.weebly.com/uploads/1/3/4/7/134716676/9f627.pdfIn PDF document text
    • https://pozategon.weebly.com/uploads/1/3/2/6/132695347/2a255e.pdfIn PDF document text
    • https://wirujiko.weebly.com/uploads/1/3/4/9/134900452/4199620.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450345/normal_5fdeefc2ae86c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/f01a5803-94af-4f56-85cd-56e209204584/6004889014.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c6f99bef-65c5-4b88-a61d-5afd62d73d75/tabla_distribucion_normal_estandar_acumulada.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/632c0f1f-be39-47eb-ad12-0f68b3e51ae5/47636257647.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cd2f8de1-f210-4608-9ec1-79953f05db2f/kepiluvetoreginimekaxufo.pdfIn PDF document text
    • http://safubudesowi.pbworks.com/w/file/fetch/144883050/94920065059.pdfIn PDF document text
    • http://wuranosa.pbworks.com/f/hobbes_vs_locke_worksheet_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b2bcfe40-7857-40eb-9790-d535f298eb5d/how_to_reset_tp_link_841n.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aba3db0d-42c7-4fa2-800c-a3d41f561cd4/poxusoxofupijisijudivan.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e1f3e581-11a6-4d90-bba0-e1a26f3cd4c9/63554726449.pdfIn PDF document text
    • http://pebokuvog.pbworks.com/f/free_verse_poetry_examples_5th_grade.pdfIn PDF document text
    • http://lekipirunezi.pbworks.com/w/file/fetch/144414402/joderugumodomodibijowi.pdfIn PDF document text
    • http://goxeguj.pbworks.com/w/file/fetch/144816960/10612166998.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_off0000e99c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE99C 5636 bytes
SHA-256: dcd55d4d5d4762276c27650c3daecaf86076f805b2d9290a256862c57bd68712
font_01_sfnt_off0000fcaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCAF 10716 bytes
SHA-256: ce74aaa71accb94cdd4b058c24e553403a3289e0d45b6c9c9a20cfc4e0d8fae3