Malicious PDF — malware analysis report

Static analysis result for SHA-256 55ad9fe31ec0617d…

MALICIOUS

PDF

79.6 KB Created: 2021-06-21 05:07:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e77efe65586de8a59c2c23e700f54512 SHA-1: c24696f647b93843f087adf881ff89fda867bb61 SHA-256: 55ad9fe31ec0617d37b33ca7d0054c1115d8b061ec4760543622cfc33105c342
164 Risk Score

Malware Insights

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

The PDF file is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm hosted on compromised WordPress sites. The document body, though heavily obfuscated, suggests a lure related to 'Biochemistry lab safety rules', which is paired with numerous links, some pointing to potentially compromised upload directories. The presence of external URIs and the overall structure suggest an attempt to redirect the user to a malicious payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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 http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160c429d36eab5---gipudaguvabemibo.pdf
    • http://alexhofford.com/temp/files/file/22277730212.pdf
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/ebc62ac2b038d58a8c2e355726124896/12289447445.pdf
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16096f69b136df---visuw.pdf
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/4dfa4e897af3a10b699dcb977f3fde7b/sozebisuxifatej.pdf
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16076f8313c578---69483306940.pdf
    • http://paulsaperstein.com/userfiles/files/xetunatetoxarula.pdf
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cac61da965---30656039644.pdf
    • https://cuisinescartier.ca/upload/editor/file/gexobemebasoxawe.pdf
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/30121ec6ad5547f6f45d1b73f01a2226/rijokewegadewewenuwiw.pdf
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/fetexikuboxaliriji.pdf
    • https://baongochoa.com/upload/file/baseparitim.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce914a05b3---rimusuzol.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b8364991031---27127764409.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=biochemistry+lab+safety+rules
    • 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_off0000f8f4.bin
754514bc2f1ed9f3364250bc0f56624946f9d4c57eb35bb142d009a127a9c155		 pdf-font-stream PDF embedded font (sfnt) at offset 0xF8F4 5412 bytes
font_01_sfnt_off00010b3d.bin
ab576a277856747f1dbf87b37e8f9d2de68f6a40a1c196877f7674ba4addb30e		 pdf-font-stream PDF embedded font (sfnt) at offset 0x10B3D 11324 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.