Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a2706d5d6dc2eda…

MALICIOUS

PDF

81.4 KB Created: 2021-02-21 22:41:34 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: 21a7b370d02ac4be044f2324f3a253b3 SHA-1: dcfd610d4493c4238f8dd961e6da2754657106f0 SHA-256: 5a2706d5d6dc2eda18c4f22c9e86e3180ab479cf78ab4943cf635b4cf2bc0bef
134 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

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

The PDF contains numerous embedded URLs, with one specifically pointing to 'jacksth.ru' and containing a UTM term suggesting a search query. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates a large number of links on disposable hosting, and the 'ML_NYX_PDF_MALICIOUS' and 'CLAMAV_DETECTION' heuristics confirm its malicious nature. While no scripts were explicitly extracted, the presence of external links and the link farm heuristic strongly suggest a phishing or content-luring attack vector, likely delivered as a spearphishing attachment.

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 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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/123?utm_term=is+game+of+thrones+book+6+out+yet PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4493881/normal_6029b5b897717.pdfIn PDF document text
    • http://lefuvaguvupawax.iblogger.org/uniforme_significado_espaol.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369783/normal_60203d9a88db7.pdfIn PDF document text
    • http://afracheat9.xyz/fadibililixuxedaxefojititgyv88.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4374380/normal_6006a3452fa25.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4406229/normal_5fdcfe77bad00.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365541/normal_601ec986b3a02.pdfIn PDF document text
    • http://genusadnlo.space/ao_smith_water_heater_parts_manualbw235.pdfIn PDF document text
    • http://file-id.ru/safagidonawamhbiyv.pdfIn PDF document text
    • https://bajorenurelop.weebly.com/uploads/1/3/0/7/130739037/wojufalagezugubop.pdfIn PDF document text
    • https://mefirotevi.weebly.com/uploads/1/3/5/3/135314773/tepixozuto.pdfIn PDF document text
    • http://mastera-saydinga.ru/mr_majnu_bengali_subtitlestyrna.pdfIn PDF document text
    • https://fepunasavejupab.weebly.com/uploads/1/3/1/3/131381111/fiwinefomolepokon.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/sowirutelevolur/pudimemofuwawadelod.pdfIn PDF document text
    • https://s3.amazonaws.com/vifusupegiza/bansuri_flute_music.pdfIn PDF document text
    • http://jijabivu.epizy.com/formica_sheets_for_table_tops.pdfIn PDF document text
    • http://saxopevatilu.rf.gd/ib_computer_science_internal_assessment_guide.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_off000101a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101A5 5544 bytes
SHA-256: 3b545ef27bd81d34530961ee6b9ebb16d08f157d863b70071fa21d2787a27005
font_01_sfnt_off00011466.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11466 10728 bytes
SHA-256: 40a5589a4499d802d480c17506291dd608f074c92a2f24b9fec93af4cafc8f48

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