Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8158adcff1d7a8c…

MALICIOUS

PDF

70.1 KB Created: 2021-02-25 18:43:20 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e6eaae764f665feeb474c1b2c93acc02 SHA-1: 7233918b62b56f6f627e9c49d9f28b22323b066a SHA-256: b8158adcff1d7a8c4448cb7e06e1f978706825e17d3f7a6e37767adf9bf4b5b6
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which are dynamically generated, suggesting a link farm or SEO spam operation. The ClamAV detection and ML classifier indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jacksth.ru/wix?keyword=ap+computer+science+study+guide
    • https://cdn.sqhk.co/busumodofu/U4gjAZw/portal_quest_fantasy_examples.pdf
    • https://cdn.sqhk.co/gixelotopa/Fhaifie/fab_t_mobile_app.pdf
    • http://gowanenutik.mypressonline.com/errores_tipo_1_y_2_estadistica_inferencial.pdf
    • https://cdn-cms.f-static.net/uploads/4502245/normal_600fcf541b99f.pdf
    • http://kakafeg.scienceontheweb.net/dalivudixosinunex.pdf
    • https://cdn.sqhk.co/dijabidasu/qjcjikC/16562387564.pdf
    • https://lifinupal.weebly.com/uploads/1/3/5/3/135336288/vebagibo.pdf
    • https://foboxujegi.weebly.com/uploads/1/3/4/6/134694162/rudelikuxorosol.pdf
    • https://static.s123-cdn-static.com/uploads/4386080/normal_5ff32a7752771.pdf
    • https://gakafapokizi.weebly.com/uploads/1/3/5/3/135319358/d5da63f9e.pdf
    • https://cdn.sqhk.co/tibatojo/ihe6efZ/80s_music_playlist_rock.pdf
    • https://cdn.sqhk.co/datimemovuko/geHQYhj/72348658145.pdf
    • https://cdn.sqhk.co/xemugugafot/vhicmjg/pico_rivera_sports_arena.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://roxonotagake.rf.gd/preguntas_ser_bachiller_sociales.pdf
    • http://gezexibubaju.rf.gd/ap_anganwadi_application_form.pdf
    • http://zapofekeba.rf.gd/80706447988.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_off0000d59c.bin
9687ef8efe6699f1c1bab4304995e3741e82db2608af65ab5071297c27cc6c59
pdf-font-stream PDF embedded font (sfnt) at offset 0xD59C 5244 bytes
font_01_sfnt_off0000e768.bin
92e5045fafb178ab461e3bd09e2301e4509b739a8aa6d1515b8034b6f8480bd3
pdf-font-stream PDF embedded font (sfnt) at offset 0xE768 10624 bytes