Malicious PDF — malware analysis report

Static analysis result for SHA-256 fa81b5cfb46186ad…

MALICIOUS

PDF

79.1 KB Created: 2021-06-09 23:31:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: 83e60546d9cf9a695db90c5857c10ae9 SHA-1: b4eb7d4df1bc0db80cf89f838db5c322bb538148 SHA-256: fa81b5cfb46186adc46cc2dea3745b4a5365fa66d7c3a6e113b72d9e6a7b3c03
156 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains a link farm pointing to multiple compromised WordPress sites, likely serving as a distribution point for malicious content. The presence of external URIs and the nature of the heuristics suggest an attempt to trick users into downloading further malware, possibly disguised as software like 'file manager pro mod apk'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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://infrive.ru/uplcv?utm_term=file+manager+pro+mod+apk PDF link annotation
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b44582f394c---1553629965.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607d0f24baa86---17297454316.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file/%5C/nenunowasotole.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a149b1bdc7c---topazofuxakatiwaginiwupi.pdfIn PDF document text
    • https://biovuspharma.net/userfiles/files/vufipewifakawupok.pdfIn PDF document text
    • http://travellightnepal.com/userfiles/file/25350962699.pdfIn PDF document text
    • http://xn--aknmedikal-yub.com/uploads/file/26338105292.pdfIn PDF document text
    • https://cedarcreeksauce.com/wp-content/plugins/super-forms/uploads/php/files/3f083adf2c9581514788e07fa97572a1/4224041679.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093afff02bfb---nusilipinedalewadagep.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8ac522388---32711665674.pdfIn PDF document text
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cccbdee661---botur.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ca6091069d---juledorade.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/ebe7021e6acb1c6210edb9dbc40947e6/kesigoso.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/04a2a6445d2c2db506fd1a86b51add1f/29554659306.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/tqs9533u6qccteaoi8hi66gl0f/wujevi.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160973620c1774---mawijuze.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC5E 5120 bytes
SHA-256: 9211cd984b37fc2fb2325b40db9ee904aaf0597bf5ede61fdfa9b2f73491a961
font_01_sfnt_off0000fdb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDB6 22196 bytes
SHA-256: 96d75a4fc4b00a4332a9136609d702c7c2f386e1acd6faf67ae3eb1e1df567c3