Malicious PDF — malware analysis report

Static analysis result for SHA-256 483765137f4114e2…

MALICIOUS

PDF

71.4 KB Created: 2021-03-17 23:07:01 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 9b8661bcbb59860bc3145be54c93c24e SHA-1: 5b5b0839655c1a3832403cbfca0e4f87807ae32b SHA-256: 483765137f4114e2584fdf07cfea5dccdd315ebb0ac56d4bd8b2674032b2ec4d
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with one heuristic specifically identifying a 'PDF_SEO_LINK_FARM' suggesting a large number of outbound links intended for SEO manipulation or to host malicious content. The ClamAV detection and ML classifier strongly indicate maliciousness. The primary malicious URL identified is https://pelibifir.ru/award, which is presented in the context of academic referencing, a common lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://pelibifir.ru/award?keyword=harvard+referencing+website+example+pdf
    • https://jitebogegamoma.weebly.com/uploads/1/3/4/7/134761197/nupafopolidap.pdf
    • https://zajebujop.weebly.com/uploads/1/3/4/9/134902249/7aeae.pdf
    • https://wanesibib.weebly.com/uploads/1/3/4/5/134591449/8e392c3bb.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://narivisifan.rf.gd/rivon.pdf
    • https://s3.amazonaws.com/kesumasaka/march_2019_sat_math_answers.pdf
    • http://gudenojotu.epizy.com/30804817050.pdf
    • https://uploads.strikinglycdn.com/files/256551af-9008-4df4-a84c-d5eca7d99c1a/wekogaxoji.pdf
    • https://s3.amazonaws.com/liwara/informacion_alimentacion_saludable_wikipedia.pdf
    • https://uploads.strikinglycdn.com/files/4574d721-0196-4bd4-b3bf-9e1c500111fe/sony_icd-px440_stereo_ic_digital_voice_recorder_built-in_4gb_and_direct_usb.pdf
    • http://jojisoxig.epizy.com/nokezavabag.pdf
    • https://18e7ef82-5c75-44fe-ae22-4c356c2c9ce0.filesusr.com/ugd/749e61_c89fdb12370c4097ad13225b3b9eb30e.pdf?index=true
    • https://s3.amazonaws.com/fowikorejodi/andrea_mitchell_reports_8_7_19.pdf
    • https://uploads.strikinglycdn.com/files/547f745f-d464-4fe1-8002-b6ce06a5cb50/how_to_write_a_self_evaluation_on_teamwork.pdf
    • https://ca108e69-7b6b-43f0-8f16-d96ebeb8a33d.filesusr.com/ugd/79e0dc_79fafa8cdc14425db50743603769be18.pdf?index=true
    • 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d71c.bin
d28fa01d47ea6ad38a513533c033ad1e0da51b70e1efc70d6b69887acb4a5377
pdf-font-stream PDF embedded font (sfnt) at offset 0xD71C 5796 bytes
font_01_sfnt_off0000eadb.bin
b170f2dfd187eaaee8aae2398509b86f959b17683d5170df65ad7f40abcd3ae1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEADB 11200 bytes