Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb69a543e1010199…

MALICIOUS

PDF

66.8 KB Created: 2021-03-09 15:02:48 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 02c520f3de4090e3e46687897f18017a SHA-1: b9fe275899843a0ca1484ea71c7281614eabd019 SHA-256: fb69a543e1010199dc80971cda15ba4305235afb22e8fd0a8c896412a4eacade
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to other PDF files, suggesting a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly indicate maliciousness. While no scripts were explicitly extracted, the presence of numerous external links and the nature of the PDF content (luring users with a book title) points towards a phishing or content distribution scheme, likely initiated via spearphishing.

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://zajinet.ru/award?keyword=isc+class+12+biology+practical+book+pdf PDF link annotation
    • https://losuwigawoje.weebly.com/uploads/1/3/5/3/135304717/1b23a6d3ee52.pdfIn PDF document text
    • https://lupabarudu.weebly.com/uploads/1/3/1/3/131398308/4c6d6769598a.pdfIn PDF document text
    • http://lupaper.22web.org/graphing_trig_functions_questions_and_answers.pdfIn PDF document text
    • https://zeradukiw.weebly.com/uploads/1/3/4/8/134883462/xogubadetodugifamete.pdfIn PDF document text
    • https://fuxovibafisiboj.weebly.com/uploads/1/3/0/8/130874455/3436166.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/purufiz/1583741111.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/68577c28-bec7-4d0f-8f74-70dc766aa88a/4483376692.pdfIn PDF document text
    • https://s3.amazonaws.com/mexijegedakol/commando_strike_force_free_full_game.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9d233911-e193-4943-b4c2-41dc95d31c6b/58565783644.pdfIn PDF document text
    • http://zewukiro.epizy.com/nozuwedujop.pdfIn PDF document text
    • http://rakemexovujepez.epizy.com/kantar_omnichannel_report.pdfIn PDF document text
    • http://nekipusixewid.epizy.com/rpg_android_offline_multiplayer.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c5e73c71-bb24-432a-9d26-18340bc0cd9f/cuales_son_los_sintomas_del_covid_19_peru.pdfIn PDF document text
    • http://ditiruvovuluka.epizy.com/tunizidusugetibasufumufi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/338a9ec2-0a42-4fd1-af50-2af48eeba327/walt_whitman_poems_i_hear_america_singing.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/de7d9f29-3033-40bc-8b7a-d9ff03b458d2/30734303864.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/abd1c3ed-bb5f-4231-ad5a-6b464742fa81/poulan_2150_chainsaw_parts_list.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3cdff750-dc57-4f69-8562-95338e08318c/lipatotosusoterug.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6aae5b6a-6724-40ee-a5c7-24ed6596583a/bewajagamemowuzofitasopit.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_off0000c6c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6C9 5752 bytes
SHA-256: 257417bf4fde6e22dbf91d4b9bc81ae3175ed792a4916ce5efbd405554473e5c
font_01_sfnt_off0000da7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA7F 10220 bytes
SHA-256: 30dbda10301b7b44c08ad9ff08df34e65e7f85bb06cbfbdd8975f5dd069f3f8b