Malicious PDF — malware analysis report

Static analysis result for SHA-256 a57a2512f212d53f…

MALICIOUS

PDF

84.2 KB Created: 2021-03-23 15:44:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: b67a594a67eb9baf9c31854dd1a3e9b9 SHA-1: 271369c0f3306f6c90b3460c1053805c733adc17 SHA-256: a57a2512f212d53f6e30bc5bd9e18578b57933b77f8e13821a4c155bdedbf11f
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm designed to redirect users. The document body, though heavily obfuscated, suggests a lure related to 'Comptia a 1001 and 1002 study guide pdf download'. The presence of numerous external links, including one to zajinet.ru, indicates an attempt to lead users to potentially harmful content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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.
  • 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.
  • 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://zajinet.ru/strik?utm_term=comptia+a%252B+1001+and+1002+study+guide+pdf+download PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4449771/normal_604495817bdf7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413467/normal_603e7496a734e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389376/normal_5fd105f5ddaf7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4501770/normal_60044f5e9cca4.pdfIn PDF document text
    • https://tunuwadubozowe.weebly.com/uploads/1/3/4/3/134363043/7342330.pdfIn PDF document text
    • https://bugupomulu.weebly.com/uploads/1/3/5/3/135396692/rajedugiwafinigov.pdfIn PDF document text
    • https://bawusazatodopam.weebly.com/uploads/1/3/1/3/131378774/lironorewol.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446161/normal_6027c100adff3.pdfIn PDF document text
    • https://fumasidabufip.weebly.com/uploads/1/3/0/7/130775820/tejuteti.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379852/normal_604a7b56d336c.pdfIn PDF document text
    • https://pevaluxuduta.weebly.com/uploads/1/3/4/5/134502983/59e2cc.pdfIn PDF document text
    • https://tifomuzaki.weebly.com/uploads/1/3/1/1/131163977/5932851.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4392658/normal_6004ce0e1caeb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4488101/normal_5fd08d6c1b99c.pdfIn PDF document text
    • https://wapojopaboxijok.weebly.com/uploads/1/3/4/7/134747084/cd31cb62210.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/dotivaf/how_to_set_up_voicemail_on_this_phone.pdfIn PDF document text
    • https://s3.amazonaws.com/tevigotu/55184894248.pdfIn PDF document text
    • https://s3.amazonaws.com/dewutexorob/67437782831.pdfIn PDF document text
    • https://s3.amazonaws.com/pazovugal/elapsed_time_on_number_line_worksheet.pdfIn PDF document text
    • https://s3.amazonaws.com/mujesogi/badman_by_kidi_and_kwesi_arthur.pdfIn PDF document text
    • https://s3.amazonaws.com/nabifovu/arduino_setup_free_for_windows_10.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_off00010756.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10756 5692 bytes
SHA-256: f45a4e34770da12e7293deee42228338f38e2b189144dcbc5b84ac66c9169c70
font_01_sfnt_off00011ac6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AC6 12084 bytes
SHA-256: a8d0a0283710fa5c7a24b6926bbe3b2c8d69e6db4f0085fd0a7125a9555b12c7

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