Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3b6a982bbb85bbb…

MALICIOUS

PDF

85.5 KB Created: 2021-04-07 13:41:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 353386520d4fe71a69d258784d9e475a SHA-1: c4069bd80c95a6c6789af1904ec7021902e27a5d SHA-256: a3b6a982bbb85bbb74d9d8d3d8bc8b55b64cd45681fdebfbf047cc580dfa28b1
226 Risk Score

Malware Insights

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

The PDF document contains numerous external links, identified as a link farm, with several pointing to potentially malicious domains. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the embedded URLs are the primary indicators of compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://baarspo.ru/123?utm_term=a+kannada+movie+upendra+songs+free
    • http://wagezofon.iblogger.org/45356468323.pdf
    • http://psychologyrelax.xyz/wiroledadixzjm3f.pdf
    • http://loveantravel.xyz/a_pessoa_que_amo_in_englishuaysi.pdf
    • http://kayikciakademi.com/kavakowaforegarituxezugoxyfxdp.pdf
    • http://didanak.22web.org/tixisawavo.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://6dd05bf8-a32e-4ce7-8057-9a1894012cff.filesusr.com/ugd/4ce960_6cca5c17ae404d8d93c62c0d53ce3d66.pdf?index=true
    • https://69b3109a-7cce-4514-9193-d2106d9976ab.filesusr.com/ugd/3c2969_dea69bf2ddfb433db5da7bfb651f1961.pdf?index=true
    • https://cf176ec6-4820-456b-adf9-61e5f06c968f.filesusr.com/ugd/43d598_92269ab898cb4cd2b6003bd02c9ef321.pdf?index=true
    • https://123949be-7110-4ba3-a240-a7df06fb38ce.filesusr.com/ugd/80fd5d_9a005ec808364686a3937ddd292e4e98.pdf?index=true
    • https://s3.amazonaws.com/lepefi/12842073666.pdf
    • https://b4140449-9b96-4148-8619-c9b3eed7b48c.filesusr.com/ugd/c33cdb_2ed4573c7b46455788c65be4cbc47e81.pdf?index=true
    • https://s3.amazonaws.com/nefomojuwet/the_painted_veil_movie_cast.pdf
    • https://f516a5e5-1936-4b34-b436-a929b3a34b8d.filesusr.com/ugd/774001_b318629427ed4b62afe8066c86efe1bc.pdf?index=true
    • https://5e73d190-47a4-4ead-99bf-7e9069f06a16.filesusr.com/ugd/55cc32_0099dd71d6934269957cf9c0c27f4e1c.pdf?index=true
    • https://s3.amazonaws.com/fenatagazise/bon_voyage_french_2_workbook_answers.pdf
    • https://b7af6bb9-01eb-4839-ab56-764651de4344.filesusr.com/ugd/2486b5_ce0b7e42900145128889b49560a34b86.pdf?index=true
    • https://d6d3a1c5-32ce-46e9-ae92-c5b8d84d65d9.filesusr.com/ugd/a3b54b_ef3d8aa024ae4108a3a10b748b06bf05.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_off0001101f.bin
048be8dc6991b03cf4aca6242b6cf9230f9dbb80994201f9b8681445914333b4		 pdf-font-stream PDF embedded font (sfnt) at offset 0x1101F 5444 bytes
font_01_sfnt_off0001229c.bin
febeb69f76dd65557a5f281ad1bce088b06c93e68854181f00155eff48e50b48		 pdf-font-stream PDF embedded font (sfnt) at offset 0x1229C 11324 bytes

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