Malicious PDF — malware analysis report

Static analysis result for SHA-256 a23771b872edefa9…

MALICIOUS

PDF

72.7 KB Created: 2021-04-04 22:14:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 52007c91d1a81458d504f40f812d2c34 SHA-1: 7dbd09cc8eb4704af215e426dd63cde65bae9fd6 SHA-256: a23771b872edefa9d772318b8d136534dd48385df94a433ef86158499fbeded0
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF document that contains an embedded URL pointing to a suspicious domain, identified by ClamAV and ML classifiers as malicious. The document body, though partially corrupted, suggests a lure related to a 'free pdf download', likely intended to trick users into clicking the malicious link. The primary IOC is the external URI used for the malicious download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 4

  • 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://nipisod.ru/strik?utm_term=french+wine+for+a+flat+belly+free+pdf+download
    • https://cdn-cms.f-static.net/uploads/4491433/normal_6030195067944.pdf
    • https://cdn.sqhk.co/woledowo/mhbYjje/rexenevepap.pdf
    • https://static.s123-cdn-static.com/uploads/4382414/normal_5fdd7a6991933.pdf
    • http://wupemokabate.scienceontheweb.net/c_language_technical_interview_questions_and_answers_for_freshers.pdf
    • http://naturwows.space/bully_max_high_performance_ingredientsiqu8o.pdf
    • https://cdn-cms.f-static.net/uploads/4465935/normal_6036fcec9e481.pdf
    • http://worldhold.online/8276797699lgf0y.pdf
    • http://tesupelaj.sportsontheweb.net/probability_questions_and_answers_university.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/4da82787-3a5a-4ce1-9854-c748008819c8/how_hard_is_shrm_certification.pdf
    • https://uploads.strikinglycdn.com/files/37347c2c-ab0e-4854-a028-9f36e7eac576/how_to_reset_nook_hd.pdf
    • https://uploads.strikinglycdn.com/files/52ff6835-608a-4cda-a3c8-154936aedaca/zororujibosexunoj.pdf
    • https://uploads.strikinglycdn.com/files/b7ad372c-f2e3-49be-9f64-ae636ba9901c/naziveberobez.pdf
    • https://uploads.strikinglycdn.com/files/a878630b-8862-4b2d-8e06-82834e7dd855/99602274160.pdf
    • https://uploads.strikinglycdn.com/files/fd9722c4-aa64-4160-85c4-7cf806e41664/graco_double_stroller_ready_to_grow_recall.pdf
    • https://uploads.strikinglycdn.com/files/673363a2-f4c0-4368-8a6e-cd87303c541f/fomututagitunabisopejako.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dcc2.bin
acc3caa4f7796414cb2a68362e0e3b42e9119829ad4c66109b5c0ec52633fbea
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC2 5352 bytes
font_01_sfnt_off0000ef08.bin
f05f7da2d186d7d97893e748248759ac2182df635605d271aad9f9c7af958769
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF08 11604 bytes