Malicious PDF — malware analysis report

Static analysis result for SHA-256 9acb08855a697503…

MALICIOUS

PDF

78.2 KB Created: 2021-06-13 08:30:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 51c00624f7eeaf1fa8cc1d8efcc358de SHA-1: 1327f060bc9ad53f77b1d69207c90f01beb08ce0 SHA-256: 9acb08855a69750358c4325bee257e383fb7be0cf049de99c5813565f040da7f
104 Risk Score

Malware Insights

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

The PDF file is identified as malicious by an ML classifier and contains multiple heuristics indicating it's a link farm pointing to compromised WordPress sites. The document body, though heavily obfuscated, suggests a lure for downloading a "Reasoning book for bank po pdf download". The presence of external URIs and compromised CMS upload links strongly suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://medvor.ru/uplcv?utm_term=reasoning+book+for+bank+po+pdf+download PDF link annotation
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/bec55c923bef9337d04c9634d08faeb5/lelofot.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/4585b630670f4abdfb4092cfb86f76a2/29256939937.pdfIn PDF document text
    • http://kibbkw.com/uploads/files/64611158372.pdfIn PDF document text
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/4f832dcd517a96db1d114aa64e75ebe8/7534798327.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/57d5038b3d10365edca63427e246b2b8/fofajifiwasopajikuvojixad.pdfIn PDF document text
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/3na9hb4e2jg03l0a9f57ba1bit/papamamuvejej.pdfIn PDF document text
    • https://bayardplaza.co.uk/wp-content/plugins/super-forms/uploads/php/files/i9m88s84agjoa5nap1ts1bb92o/51330239162.pdfIn PDF document text
    • https://cgeminfos.ma/upload/file/tumeje.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/160b06a207caf2---20026986692.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/4ea8f858b1c43a2053d43e27d49ef7f3/mikigabipizus.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b9d0e914964---96056304330.pdfIn PDF document text
    • https://ipic.vn/userfiles/file/renam.pdfIn PDF document text
    • http://caphegiabao.com/upload/fck/file/49375645297.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/7e49d0b0dbd1624b2d1382e36bb31c6c/sozuwosaw.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/97103100373.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF40 5512 bytes
SHA-256: 5dcd7dac4952e0bf356c1d3cfaccbb61998803bbded135f68e54aaacd42b5063
font_01_sfnt_off0000f225.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF225 10616 bytes
SHA-256: a3643074b4cd9073bfed346fc47d748de4512a82f26b311bbdba4a42445eddc9
font_02_sfnt_off0001167b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1167B 16164 bytes
SHA-256: c41fc46809d2260d2d1a821cef6bb00dae560fdbad380da94a93f29d012df54e