Malicious PDF — malware analysis report

Static analysis result for SHA-256 a25e0c62cec50e77…

MALICIOUS

PDF

99.1 KB Created: 2021-03-08 13:40:59 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 01b6524c27d8816d789f5ac2d3bb9f6e SHA-1: 2aa63fb6ad1bdf5807d7816d73da8a46c6d6629e SHA-256: a25e0c62cec50e7726020e35a25fbb59d43181964929f52f16e159c91640aec6
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO poisoning tactic. One of the primary URLs, 'https://nipisod.ru/123?utm_term=evidence+of+evolution+fossils+worksheet+answer+key', is associated with this malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nipisod.ru/123?utm_term=evidence+of+evolution+fossils+worksheet+answer+key PDF link annotation
    • https://bebezirowud.weebly.com/uploads/1/3/4/3/134371107/8301675.pdfIn PDF document text
    • https://damozudi.weebly.com/uploads/1/3/0/7/130776403/7495050.pdfIn PDF document text
    • https://xebuzoxovekig.weebly.com/uploads/1/3/4/0/134018553/2218137.pdfIn PDF document text
    • https://vogapixafaroge.weebly.com/uploads/1/3/4/2/134234717/dirag.pdfIn PDF document text
    • https://buxarurusej.weebly.com/uploads/1/3/1/8/131856129/377a30594b7d3f.pdfIn PDF document text
    • https://nufusuninad.weebly.com/uploads/1/3/4/6/134609023/040c85fb.pdfIn PDF document text
    • https://werotibumef.weebly.com/uploads/1/3/4/9/134900185/vajapajef.pdfIn PDF document text
    • https://zezonusadife.weebly.com/uploads/1/3/1/4/131410479/jugokipuwumapadadex.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cf587a47-7c2f-4f55-8bbb-21a4c73503f7.filesusr.com/ugd/8ea597_de5051697af64a558df9f591d21bda85.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/robumuduluwise/adobe_after_effects_twitch_plugin_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/573f7301-f323-4dd1-b911-6625da144c32/81624858122.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f253f0c7-892d-4e1a-a092-1337e7a2902e/aprender_ingles_para_nios_de_4_a_5_aos.pdfIn PDF document text
    • https://d1897088-ef6e-4b60-8303-910b4b551fc1.filesusr.com/ugd/4cfbbd_03f080d820634a04934f90fd8c010a87.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/0f9fa928-6f84-4b62-bc83-72fce1aa4fdd/99060561798.pdfIn PDF document text
    • https://c78267de-509c-4cb0-9394-6b21b7876e04.filesusr.com/ugd/290ce3_1f35254644344e359a1d3e1311f28ee6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tobovunoberiki/amma_amma_asai_amma_song_audio.pdfIn PDF document text
    • https://s3.amazonaws.com/loranoduzuja/najufepuvaxufukobekudo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bd1b3bf2-6b8b-467f-8f8f-29256878c7d8/wavipunisenonupame.pdfIn PDF document text
    • https://s3.amazonaws.com/zifilobesumafi/bind_service_example_android.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_off00014814.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14814 5384 bytes
SHA-256: e8906e9d2377f54303ff42ce55e408e4cfa4852b07ef6bc1231b5c6cf57acce3
font_01_sfnt_off00015a82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15A82 10760 bytes
SHA-256: 67bf5f988ec6a6ad547f0de7e85e46af7a8cedb61e415d95904f91866b503dbc