Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3d0f2545759a6d4…

MALICIOUS

PDF

81.3 KB Created: 2021-05-20 07:51:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 173246b963f05f74ca4434351c1f82e3 SHA-1: 1f1652864a3a5a900d43cab214c031f3c9795266 SHA-256: f3d0f2545759a6d49cece6ed8ffedfa9784de97df44639ae3b42e5e439ec6bef
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with a critical heuristic identifying a 'PDF_SEO_LINK_FARM' pointing to multiple PDF files. One of the primary external URIs, 'https://resalured.ru/strik?utm_term=ejercicios+de+diptongos+e+hiatos+para+4+primaria', suggests a lure related to educational exercises. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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=ejercicios+de+diptongos+e+hiatos+para+4+primaria
    • https://durunefa.weebly.com/uploads/1/3/4/7/134712847/4327764.pdf
    • https://pijuvadugodawa.weebly.com/uploads/1/3/4/3/134307721/lerapifovoduxalud.pdf
    • https://dujodorenenap.weebly.com/uploads/1/3/4/4/134488447/polofesuri.pdf
    • https://ruvezidarumova.weebly.com/uploads/1/3/1/3/131380493/4562453.pdf
    • https://relakurofur.weebly.com/uploads/1/3/4/8/134872141/b5ffe618727d.pdf
    • https://jotegeposopema.weebly.com/uploads/1/3/4/7/134743683/5408768.pdf
    • https://zurenigexozaxil.weebly.com/uploads/1/3/4/6/134606750/mavuzanidonokagaj.pdf
    • https://gasezojilatinoj.weebly.com/uploads/1/3/1/4/131455825/fbe53d029d9c3c1.pdf
    • https://dojudetokin.weebly.com/uploads/1/3/4/6/134613144/1082ee80c.pdf
    • https://mizefubu.weebly.com/uploads/1/3/4/6/134637235/mesamibesok.pdf
    • https://ruzuxopamekegi.weebly.com/uploads/1/3/4/7/134748505/mazujotemoxenab.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/pusori/sebijidofibu.pdf
    • https://s3.amazonaws.com/purixifusipelid/rufaxuredamelekenidirisuw.pdf
    • https://uploads.strikinglycdn.com/files/cf6a1c02-255e-4bb5-ac14-842e84f8c162/pupuvorimenavogufutuj.pdf
    • https://s3.amazonaws.com/naxozelozude/2536949564.pdf
    • https://uploads.strikinglycdn.com/files/4d6ede46-f4d1-4374-b635-3471ccc4afaa/what_is_free_cash_flow_of_a_company.pdf
    • https://uploads.strikinglycdn.com/files/0bd03ee8-a12b-4b79-9b01-621183bcd631/the_giver_chapter_13_and_14_summary.pdf
    • https://s3.amazonaws.com/jifesu/gomufawiruwakazekedolive.pdf
    • https://uploads.strikinglycdn.com/files/062e237d-8901-468f-b25d-a105759c6592/insurance_fraud_investigators_salary.pdf
    • https://s3.amazonaws.com/bokofapig/vuxozukumimufanowonoluzu.pdf
    • https://uploads.strikinglycdn.com/files/c522d657-56e2-44b0-b241-cfc102656637/59180163796.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e40c.bin
6a6bd26f251bcd45637cd3f845b4e56f3f6cfb0aa8131c3fcd88a0a68fda0253
pdf-font-stream PDF embedded font (sfnt) at offset 0xE40C 5576 bytes
font_01_sfnt_off0000f6ec.bin
e14c9e085616bd541b2bd88a0c5106e6d4806a3ffe467eda9abf4435e2e3bef3
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6EC 13420 bytes
font_02_sfnt_off000121b3.bin
7f64a184185b19c4509fb58d2bd1b04ad0bf592a661abde0780cedf99fd3e42e
pdf-font-stream PDF embedded font (sfnt) at offset 0x121B3 16164 bytes