Malicious PDF — malware analysis report

Static analysis result for SHA-256 c423965b52bccee1…

MALICIOUS

PDF

79.2 KB Created: 2021-06-22 11:44:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: e5bc1f46a6b190f45daff7b4d75f47fb SHA-1: e0431a05c1529e204c57861f7810f20f5699cfe3 SHA-256: c423965b52bccee1de0ed90f7fbe674734dd1fbb65420a7b2ae80b54d3c5d1c5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or SEO poisoning campaign. The document body is heavily obfuscated, preventing a clear understanding of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 http://apsencollege.org/test/fckeditor/file/taduxipupifal.pdf In PDF document text
    • http://temple.mo/userfiles/file/9240508890.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/b9df45965c48f740435554826e4fc9d1/begowowifesumefa.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d3b06a0716---60647723676.pdfIn PDF document text
    • https://fotofidelity.cz/userfiles/file/pajedujugufesilopuzatoki.pdfIn PDF document text
    • http://mestav.sk/uploaded_images/file/ruzelopiremidisar.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/a845b69d447c1569299c63fd91f4596a/bajolufar.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c1ebe191b1---zivimuradufejika.pdfIn PDF document text
    • https://aashianarealty.com/file/fujevagol.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/lewomirerixuwede.pdfIn PDF document text
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/r6d88168ht8embq2vuc8l3o7t7/wizoj.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070f7ec3486d---88170804062.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=debussy+dr+gradus+ad+parnassum+pdfPDF link annotation
    • 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_off0000ef61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF61 5572 bytes
SHA-256: 0585c3c1427c542b0f64d3bd53d67f2078d8c749e8ba8b960a78994abcbc8c6c
font_01_sfnt_off00010246.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10246 13876 bytes
SHA-256: 7c97361f720e23fe3c74b7c7a07c35a853b2e2ad6df99e49edfb8775713f48f9

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