Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8db03c30e012dcb…

MALICIOUS

PDF

76.3 KB Created: 2021-03-25 02:55:16 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: b21c3cbbb72306991e3b3c37c2ca4874 SHA-1: 7a0eb2161535a5d477ca3eb9edf1b426a057b5f7 SHA-256: c8db03c30e012dcb6f8d67239bbf62b6718af6e63a9b24159acf88e7a0b70258
186 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

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

This PDF file is identified as malicious by multiple heuristics and a machine learning classifier, specifically flagged as a phishing trojan. It contains a large number of external links, many pointing to disposable domains, suggesting a link farm or redirection scheme. The primary purpose appears to be directing users to potentially malicious external content, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://vilenefex.ru/wix?keyword=think+big+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4386073/normal_602a7d19cfc3b.pdfIn PDF document text
    • https://cdn.sqhk.co/guzoladip/gvkmZkj/us_history_quiz_11.pdfIn PDF document text
    • https://fokinovev.weebly.com/uploads/1/3/0/7/130775288/wezunase-winefupiz-vixibugezafel.pdfIn PDF document text
    • http://premial.su/how_to_pair_logitech_k800y0awi.pdfIn PDF document text
    • https://cdn.sqhk.co/sozodumupof/jbrijoO/tofalewono.pdfIn PDF document text
    • https://cdn.sqhk.co/nevupediwix/iggjeha/betobagepujotokepewuz.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368485/normal_5fd15520888fb.pdfIn PDF document text
    • https://cdn.sqhk.co/lewulula/ijghzje/sticker_maker_2020_app_download.pdfIn PDF document text
    • http://goldstein.berlin/2211670132903xrv.pdfIn PDF document text
    • https://kagoninu.weebly.com/uploads/1/3/1/4/131453226/jizoturipatig.pdfIn PDF document text
    • https://cdn.sqhk.co/sojuzafu/gW106ij/duxojenasukiduretuset.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://0b609444-e5a2-4a7e-9779-a3c6bae51a53.filesusr.com/ugd/529dbf_16c3dd2bb4b54dbead4125bbe4a45717.pdf?index=trueIn PDF document text
    • https://c2267750-1f6d-4c2f-944a-eb302c7f07d7.filesusr.com/ugd/93971e_e86e38d3e70a4481af30251b84401a31.pdf?index=trueIn PDF document text
    • https://98748e4b-3258-471a-903e-8ea98415cca0.filesusr.com/ugd/fd7405_ce0699dcab10493bb09a7cde91595bc3.pdf?index=trueIn PDF document text
    • https://d6bf9bfb-c092-4b17-ab9f-91da83e6a9d2.filesusr.com/ugd/d7ad14_030d35edc84f4392b42b5b40e659e813.pdf?index=trueIn 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_off0000ebe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBE0 4940 bytes
SHA-256: eb01faebdc459a2fa036bf93fdbaa90e38b096baee1512588106b28497af9aed
font_01_sfnt_off0000fcb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCB3 12028 bytes
SHA-256: a5b9c83e1dce0be20dcfa45ba7ba456e0c2cf7f0c56622fb4e1fca6a8ccc6a97

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