Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8b2a94c3e5fd35c…

MALICIOUS

PDF

77.1 KB Created: 2021-06-09 00:17:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 78f9dcf14a0bf5ced875742e9354f26b SHA-1: a9507f2e27abbf3b5403f3bfa27e4658a45d22fb SHA-256: d8b2a94c3e5fd35cf1ceb5a7bca27cac85c372deeaaae461e2a2a614a41f739f
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs, with one prominent URL pointing to 'cructi.ru' and a related link farm heuristic indicating a disposable hosting setup. The document body, though heavily obfuscated, contains text related to PDF compression, suggesting a lure to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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 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://cructi.ru/pbw?utm_term=compress+pdf+to+900kb PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4418985/normal_6054ed04293ff.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4416805/normal_5ff9a72ddc4ed.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408002/normal_5fda49c90bb4f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476418/normal_606e7843a7353.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4484994/normal_5ff1d1302743e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385422/normal_5fc95d69b7a9e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459641/normal_5fd326009fa4a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414486/normal_602e0820490be.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wusagem.pbworks.com/f/54226416027.pdfIn PDF document text
    • http://fubajulak.pbworks.com/f/adding_ing_to_verbs_exercises.pdfIn PDF document text
    • http://zevatirupura.pbworks.com/w/file/fetch/144625413/23614670784.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9686cb23-34bc-4188-9d1a-a0c763682cad/bobononamagubitojawag.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/60956e74-5e18-4d33-8d45-88597b85383c/12989528526.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e927a0dd-8541-45aa-a376-5595dd1b1b35/basic_principles_of_quantum_mechanics.pdfIn PDF document text
    • http://motekus.pbworks.com/f/85580056560.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cd768bfd-4086-4196-97b3-cac591c8587b/the_mediums_book_allan_kardec.pdfIn PDF document text
    • http://motekus.pbworks.com/w/file/fetch/144889947/mi_launcher_pro_apk_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0ff1f721-e79a-4fc1-886f-b0f7633575ad/is_bonding_good_netflix.pdfIn PDF document text
    • http://zufogopojut.pbworks.com/w/file/fetch/144596487/how_do_you_write_2_hundredths_as_a_decimal.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8a45ec74-5c0e-459f-8257-dcc58f3cdc24/words_their_way_within_word_pattern_spellers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/da12711a-996b-410b-8527-a2766a33ac12/3575218828.pdfIn PDF document text
    • http://kibumezi.pbworks.com/w/file/fetch/144710943/future_simple_active_and_passive_exercises.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_off0000ef49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF49 5352 bytes
SHA-256: 628efc2a6a582ebbba59c51b0bcc8704bfc3062df3980fe138694cc4f3f8ea44
font_01_sfnt_off0001015e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1015E 10696 bytes
SHA-256: d76fafdafe9aa8653908d2d2fe6a1808042d73e3b412d0b1040de6ceaf97505c

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