Malicious PDF — malware analysis report

Static analysis result for SHA-256 621cd15c521ec827…

MALICIOUS

PDF

85.5 KB Created: 2021-03-14 17:20:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 59de31c1444e967728f384f4d66bb563 SHA-1: 2764e9428ae5c81194f10e3d4336890d43d11d60 SHA-256: 621cd15c521ec827974f28c1e9c374732a2ea4456862060fe6a78c6b50391cd3
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as phishing and trojan activity. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing attack leveraging a lure of popular search terms to disguise the malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 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://jumiwimov.ru/award?keyword=bohemian+rhapsody+piano+sheet+music+original+pdf+easy PDF link annotation
    • http://lenulari.mypressonline.com/pdf_marketing_management_kotler_15th_edition.pdfIn PDF document text
    • https://cdn.sqhk.co/sututidogo/heA8yha/gavuzoz.pdfIn PDF document text
    • https://cdn.sqhk.co/kulobibab/epTkhho/85618823959.pdfIn PDF document text
    • https://cdn.sqhk.co/janonaset/ghfjbjg/mukejewuluwu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370304/normal_5ff692a8bd4a7.pdfIn PDF document text
    • https://cdn.sqhk.co/vizakifito/hhkjijh/balurasekalozeti.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368237/normal_5ff4bd3359520.pdfIn PDF document text
    • https://cdn.sqhk.co/lodikorep/jhlgeha/25590725291.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://28a90398-13b1-4b58-b54c-ed045a6bddf2.filesusr.com/ugd/7e9e1f_5e5e6c1d8bc04c8e8075945b1524ecf3.pdf?index=trueIn PDF document text
    • https://0ecef3a8-5193-4df1-8dcb-1b7dd0f2be2a.filesusr.com/ugd/e6092c_f6e8abe45bf34686b8e23de1fa56b0e4.pdf?index=trueIn PDF document text
    • https://6448a590-b571-4b71-a9e4-820b8531b153.filesusr.com/ugd/782be2_99b334ff4df647b69f3c9601902ea148.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a5b31cd3-114f-4418-9f80-a6fb4d37657b/40955134417.pdfIn PDF document text
    • http://xemigososefof.atwebpages.com/duzoluganiriwuwaludorok.pdfIn PDF document text
    • https://6974b9b2-fc2a-4e9b-9495-84ff65489eb7.filesusr.com/ugd/395280_d741986fd428436a95478a96a6fc44c5.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/69dc701e-c15d-405f-8ea9-1f41fb0adc8d/how_to_fix_capitalism_porter.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/553a318a-24a7-4dd9-9f36-8c1e97ac9fe8/7354357652.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f9ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9AC 5720 bytes
SHA-256: d240aab4c6b13aecf4e0e7c9f68c671df0095d159327f37397548f14d4130e29
font_01_sfnt_off00010cfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CFE 11364 bytes
SHA-256: 4b0a8ff214fba7051d9c30b0bc5ada0142be7eaa4fb08d2fab6764907d95dbbb
font_02_sfnt_off00013374.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13374 16100 bytes
SHA-256: b59afbb2f683942213df284fd86cd9422ada0c5f1ffac7698db8c94a40390bc4