Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba83a3a22d069d40…

MALICIOUS

PDF

69.0 KB Created: 2021-06-21 17:05:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: ce8c293ec27e962e34b0a8c5c7e2308c SHA-1: 31a5d37e70202f006c90865e30536fa571736a14 SHA-256: ba83a3a22d069d40b47ace80e4335dec65591267ec5da4c3019f216c79ec3b75
164 Risk Score

Malware Insights

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

This PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to various PDF files hosted on compromised websites and disposable domains, suggesting an attempt to distribute further malicious content. The document body, though heavily obfuscated, appears to be a lure related to educational materials, likely to trick users into downloading the embedded malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • 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://unserbiokorb.ch/userfiles/file/nezokedepasutimedojig.pdf In PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c437e08663b---gixawiriwukolugewo.pdfIn PDF document text
    • http://dekoblickfang.de/userfiles/file/tevafigajos.pdfIn PDF document text
    • http://duhochmis.com/files/uploaded/files/23087927801.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-4-29/20210429124424697353.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/515a5a0ca54ebda0d25da47832bbafc3/82449734928.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/ch1341uv2ttqhq5g7efiappauk/35167201606.pdfIn PDF document text
    • http://phoiinnhiet.com/images/uploads/files/sizusotukufanodosizumej.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/0e963331cea35d8bf21ead58dd164954/99462809209.pdfIn PDF document text
    • http://amazingindiaphotos.com/amazingindiaphotos//upload/fckimage/file/46991306497.pdfIn PDF document text
    • https://agatanorek.com/files/file/zepemotaxuti.pdfIn PDF document text
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/d7d6ma4qs21b9n5rdkl7jvvppg/damofimafokese.pdfIn PDF document text
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/6966b13bec5235a4c9c4d361f4432f01/lurijakegawazajezes.pdfIn PDF document text
    • http://say-international.eu/userfiles/file/tasorojefufunikepido.pdfIn PDF document text
    • http://goref.ru/files/file/18021464847.pdfIn PDF document text
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bbdba374a8---23436870052.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/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=class+9+chemistry+s+chand+solutionsPDF 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_off0000cf01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF01 5340 bytes
SHA-256: c83a018d7185857c1d73211bbc40f62b18f3c0481e07f484a6ce18a45c2cf032
font_01_sfnt_off0000e0fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0FD 10608 bytes
SHA-256: 7912e738da1c745ed466bf35b867172274460366dbd1cc95b7bc5e22b423ed6f