Malicious PDF — malware analysis report

Static analysis result for SHA-256 83c0cbd9ddb7aefd…

MALICIOUS

PDF

73.2 KB Created: 2021-06-19 13:23:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: c40670958cfebb9258dac4de1c6f8386 SHA-1: 916fb5a5c6b3838f56732befc52e42e2d947a77c SHA-256: 83c0cbd9ddb7aefdb31c7b06295fea0936c6d35403b710a23f1d31f8cb9a58d6
196 Risk Score

Malware Insights

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

This PDF file exhibits characteristics of a phishing or malware distribution lure, as indicated by multiple heuristics flagging it as a link farm pointing to compromised CMS uploads and disposable hosting. The presence of a link related to 'sound recorder pc windows 7' suggests a social engineering pretext to trick users into downloading a malicious payload. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/b12da71a6e0bc6495813f4372e2849dd/71054423956.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6c76b4201---84179318716.pdfIn PDF document text
    • https://strategieb2b.com/userfiles/file/15497460611.pdfIn PDF document text
    • http://iccj.jp/images/uploads/fckeditor/file/voliligidur.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a702535a149---36417351107.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/xuzelovimabuzaxexawivuko.pdfIn PDF document text
    • http://augustaelectricalwork.com/editorData/file/nexujuzutisifewafiwimog.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1609bb60150807---rifuxazorunofimuti.pdfIn PDF document text
    • http://agnieszkapawlik.com/userfiles/file/kesixurusojefagiximop.pdfIn PDF document text
    • https://edu-mate.kr/_UploadFile/Images/file/39373173025.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/160794a8598aa0---53687320278.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bfb2c420158---gomosuk.pdfIn PDF document text
    • https://adepotcustom.com/UploadFiles/file/20210430091013121.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://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=sound+recorder+pc+windows+7PDF link annotation
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/9660b3102a35d9f25308b28a99a55996/lobenilos.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_off0000d251.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD251 4900 bytes
SHA-256: 3fd273191ade47f8c98ec6887af0dfe01dc872d72a672e6bb06b1b5cabe0508f
font_01_sfnt_off0000e30d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE30D 11024 bytes
SHA-256: 4278b49e96741e8c9d391e38fc4228b9f9e2c7493b122b1bd2af1fb6f3d182a3
font_02_sfnt_off0001083f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1083F 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f