Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ef17ff014aa317…

MALICIOUS

PDF

80.9 KB Created: 2021-03-17 09:42:51 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 75a0ba574d867d45f4f7fd701b00766b SHA-1: d6f5400c0e1d754c67fad3d8787fe2b151bd69fb SHA-256: 81ef17ff014aa3172891614ce6c9904bf82b24c18c8f4a4a00460da7cf2888ed
134 Risk Score

Malware Insights

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

The PDF contains numerous external links, many hosted on disposable domains, and a heuristic firing indicates it's a link farm designed for SEO manipulation. The presence of a 'download button' lure and a critical ClamAV detection for 'Pdf.Phishing.Trojan' strongly suggests a phishing or malware distribution attempt. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of a malicious document designed to trick users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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/award?keyword=ctet+answer+key+pdf+2020+download PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4425229/normal_600180ba617f9.pdfIn PDF document text
    • http://good-production16.site/aa_fourth_step_worksheetsfecyr.pdfIn PDF document text
    • https://cdn.sqhk.co/daborofus/hhhrG25/gmail_app_download_for_android_mobile.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4468836/normal_6001baa6eb55c.pdfIn PDF document text
    • https://cdn.sqhk.co/wojidumezu/Vgcidif/35913259013.pdfIn PDF document text
    • https://cdn.sqhk.co/kenipafitu/cxifDZd/first_strike_final_hour_apk_1._3._14.pdfIn PDF document text
    • http://xibomupazone.mypressonline.com/binary_numbers_addition_subtraction_multiplication_division.pdfIn PDF document text
    • http://nutusugeralinet.mypressonline.com/maze_runner_characters_newt_real_name.pdfIn PDF document text
    • http://dayzcommunity.info/56910672450pakde.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375203/normal_6021ec13abb75.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/jemisajoda/lamborghini_gallardo_price_trends.pdfIn PDF document text
    • https://36fc1fe3-b646-4cc1-b6e9-de51469aea27.filesusr.com/ugd/3eb4bd_d0f4901d04844a5eaef2fcb58d692440.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/siwixomudit/72989739320.pdfIn PDF document text
    • https://97783159-ced7-426e-9fbd-60d2bb3342fb.filesusr.com/ugd/00058f_29a66cbc671049cda704715da6580a83.pdf?index=trueIn PDF document text
    • http://sewemira.atwebpages.com/beef_pilau_recipe.pdfIn PDF document text
    • https://4ad55601-b8ab-4ae0-bc0e-e90069072326.filesusr.com/ugd/3aca14_1a04f1df46b647828422c1a7b0d240fe.pdf?index=trueIn PDF document text
    • https://36622f5a-5a1b-41a5-aa98-965156e47ac2.filesusr.com/ugd/804ff6_e3d0b70ccff0458691f609a91302ccee.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/pirofopafu/zewaxopasisuxiwit.pdfIn PDF document text
    • https://d4180a97-8dd0-4bf1-9e2f-d1b128d1a64d.filesusr.com/ugd/ae059d_5087813559b248f2a5dcc20faa26551e.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/nuxomigo/fixuxize.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE45 5328 bytes
SHA-256: d82e351b2f61e5a921d5c07776fc67d6ccf8a1db7c166aa55399924bdf25a35f
font_01_sfnt_off0001008a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1008A 10960 bytes
SHA-256: 06f5b85032f9a8868b75110b53a19773c24e0654ccde490d8e5d41e1c339b020
font_02_sfnt_off000125e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125E0 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34