Malicious PDF — malware analysis report

Static analysis result for SHA-256 91d90d94c781a57e…

MALICIOUS

PDF

86.9 KB Created: 2021-06-14 02:10:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 216a53154552ee4bbb433723498f038c SHA-1: abe3743169b052088cfff9ca2e3082b0283b55c5 SHA-256: 91d90d94c781a57e8b4b695ddee84845f292f7d51b598e86092c773bcc445933
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, directing users to multiple compromised websites and disposable hosting domains, likely for further exploitation or malware delivery. The presence of external URIs and link farm heuristics strongly suggests a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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://philabc.ru/uplcv?utm_term=50.5+euro+shoe+size+to+us PDF link annotation
    • http://mdbim.pl/ubezpiecz/obrazy/file/8493769726.pdfIn PDF document text
    • https://morabia.fi/images/file/pomupuridupi.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/d333511c8874aeebc818c085fb404c00/47733507292.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/pemomafanamezefonan.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160afddb55eb25---40959850352.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/kkd4b8prrhtls83it357k6eea6/72579105239.pdfIn PDF document text
    • http://automotiveenergy.cz/userfiles/file/vokanetexefiwovolunemi.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/8eb76620b66df9b0ad1232dde58ab5e2/75064426979.pdfIn PDF document text
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/5dd3fc5590828b2153cb249d56794a1c/66962399343.pdfIn PDF document text
    • https://gtselect.fr/ckfinder/userfiles/files/gujapovuven.pdfIn PDF document text
    • https://evg-prague.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608fd8c292416---87775680942.pdfIn PDF document text
    • http://thietbixanh.net/uploads/files/kozozu.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/2dd10000eec368cf3fb478ee2130f7cb/25094433573.pdfIn PDF document text
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/3akb4drfq3vg1j1e333q12e0f0/25074351017.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_005_off0001328f.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1328F 17960 bytes
SHA-256: 8032c0c367ec811a8ae4e7bd28ec8272a00965ca7790a17a0a72d63b3a766059
font_00_sfnt_off0000fbef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBEF 4784 bytes
SHA-256: c153d071271dbe6fd8387ae6135f7d33cb72b6fc24c2d45e97d0f07f193c4945
font_01_sfnt_off00010c3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C3E 11224 bytes
SHA-256: 2b821be33ce68a00ed18af5158fe733d1fa8b1703b9b94c03cad2f731d8dadfa