Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b21e4577bf427f7…

MALICIOUS

PDF

76.6 KB Created: 2021-05-21 12:42:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 57efbc9cdf1f4dba4839f5fed64ad92d SHA-1: 27841c6d13629c7d637bb0d5d959993e4b4977da SHA-256: 9b21e4577bf427f7b5ff078d7fb318191c1a7454ea445c3854978177818fabb8
164 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to PDF files, suggesting a link farm or a method to distribute further malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and numerous external links are indicative of a malicious workflow, possibly involving JavaScript for exploitation or redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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.
  • 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://resalured.ru/strik?utm_term=class+10+maths+chapter+2+worksheet PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4368736/normal_6066f13e20543.pdfIn PDF document text
    • https://nomomiwadij.weebly.com/uploads/1/3/3/9/133997716/a410ef442b6824.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380090/normal_602786fb3bd46.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366325/normal_600c421b49ebe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465704/normal_606793553aee7.pdfIn PDF document text
    • https://seruborakumew.weebly.com/uploads/1/3/4/8/134849990/0c1854aa875.pdfIn PDF document text
    • https://severuzilun.weebly.com/uploads/1/3/4/7/134710190/dowewikomarokolu.pdfIn PDF document text
    • https://manomukujoputu.weebly.com/uploads/1/3/4/5/134517900/c694d49c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4467601/normal_60515f2757b55.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4486363/normal_60095e5539edd.pdfIn PDF document text
    • https://fisotewefupug.weebly.com/uploads/1/3/1/0/131071176/2892426.pdfIn PDF document text
    • https://litodamun.weebly.com/uploads/1/3/4/7/134710511/nujejidawulon.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482849/normal_60664882413da.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451563/normal_6004af2566b1b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416322/normal_602f89335acab.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426075/normal_6041ef9208bfc.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/sefiwegegagu/2335322582.pdfIn PDF document text
    • https://s3.amazonaws.com/dorobukasawituw/valvular_heart_disease_guidelines_ppt.pdfIn PDF document text
    • https://s3.amazonaws.com/jumedemimo/26187646489.pdfIn PDF document text
    • https://s3.amazonaws.com/wupiwupiwot/what_is_non_woven_interfacing_made_out_of.pdfIn PDF document text
    • https://s3.amazonaws.com/fotojipifuzitul/21635255020.pdfIn PDF document text
    • https://s3.amazonaws.com/jevedijadiki/reading_comprehension_test_for_grade_12_with_answer_key.pdfIn PDF document text
    • https://s3.amazonaws.com/satedafadusizo/4095136413.pdfIn PDF document text
    • https://s3.amazonaws.com/timituvupame/lazorukolisanorusa.pdfIn PDF document text
    • https://s3.amazonaws.com/gezejoputiwinu/kiwiduborotinisituped.pdfIn PDF document text
    • https://s3.amazonaws.com/lokijuronig/adanga_maru_ringtone_zedge.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_off0000e93d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE93D 5560 bytes
SHA-256: d5aa5fea002352aac7cf097b0db5ca8f0ef53cdf69fb7385054b4727b87f02f1
font_01_sfnt_off0000fc0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC0E 11364 bytes
SHA-256: b990d36c0a31113776d773e40877d032fc9ca3c88bb748630cfc25445812bfa0