Malicious PDF — malware analysis report

Static analysis result for SHA-256 d9b1fa95f27889e7…

MALICIOUS

PDF

78.4 KB Created: 2021-03-24 08:10:45 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 4a081e13b031dbe02b1078c75055be74 SHA-1: 77e7f5a82a230ad81e436ef2540cf08f2bf909e4 SHA-256: d9b1fa95f27889e73a1b26ccdf8c930404dc0a9682702f2a4d865ed3a1c5ecdf
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a phishing or link farm attack. It contains a large number of external links, with one notable URL being https://druttle.ru/123?utm_term=swan+lake+theme+piano+sheet+pdf. While no scripts were explicitly extracted, the PDF structure and the presence of numerous external links suggest an attempt to redirect users to malicious sites or engage in SEO manipulation for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://druttle.ru/123?utm_term=swan+lake+theme+piano+sheet+pdf
    • https://cdn-cms.f-static.net/uploads/4376099/normal_5fd14963356b1.pdf
    • https://cdn-cms.f-static.net/uploads/4503787/normal_604adbeaa448d.pdf
    • https://bavanakeburosot.weebly.com/uploads/1/3/5/3/135302165/6b62fc10e.pdf
    • https://metenesepagozo.weebly.com/uploads/1/3/4/7/134710396/f68d9.pdf
    • https://cdn-cms.f-static.net/uploads/4458628/normal_605a15ab61b17.pdf
    • https://cdn-cms.f-static.net/uploads/4413866/normal_5fd862f8263e7.pdf
    • https://cdn-cms.f-static.net/uploads/4481527/normal_60332cf9367a1.pdf
    • https://cdn-cms.f-static.net/uploads/4413120/normal_5fe8a3de59080.pdf
    • https://bofakodejo.weebly.com/uploads/1/3/4/2/134265658/6361406.pdf
    • https://vumifedesonuzik.weebly.com/uploads/1/3/4/8/134849268/xepuv.pdf
    • https://cdn-cms.f-static.net/uploads/4489422/normal_6023848125271.pdf
    • http://padojobimo.mywebcommunity.org/87604685367.pdf
    • https://cdn-cms.f-static.net/uploads/4454824/normal_601c6a9ae8fb7.pdf
    • http://desajegurake.scienceontheweb.net/physical_science_grade_12_book.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/liwafo/fitness_quest_gazelle_edge_replacement_parts.pdf
    • https://uploads.strikinglycdn.com/files/1fb6a29f-4fad-4411-ae33-3fdae0ef8aee/how_to_clean_hp_7520_printhead.pdf
    • https://s3.amazonaws.com/zobuwubedak/how_to_prepare_meals_for_the_week.pdf
    • https://uploads.strikinglycdn.com/files/e424a1e9-2fd4-4680-a9a6-902e65be7d7e/fobaravinovobabimupanisi.pdf
    • https://s3.amazonaws.com/nigimul/the_secret_life_of_bees_full_movie_free_online_123movies.pdf
    • http://zusaxadixuxot.myartsonline.com/najara.pdf
    • http://zuputes.atwebpages.com/clicks_catalogue_august_2020.pdf
    • https://uploads.strikinglycdn.com/files/430892d4-0fbf-4df6-80e2-2b73aac54cc6/wuvunixoxuxasotano.pdf
    • https://s3.amazonaws.com/kigavanus/dunisapukogalajune.pdf
    • https://s3.amazonaws.com/nuselufuzo/bakuvenavobidopetejivu.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f29e.bin
85257c3f4032e905662ce19689f2966589abe2136bc1e7edc4f708469587af26
pdf-font-stream PDF embedded font (sfnt) at offset 0xF29E 5444 bytes
font_01_sfnt_off00010510.bin
a052bbafc633d42da421541835a34719f8c619bb97e0db7eb5eec55686ca2703
pdf-font-stream PDF embedded font (sfnt) at offset 0x10510 11680 bytes