Malicious PDF — malware analysis report

Static analysis result for SHA-256 88a67c7811f55425…

MALICIOUS

PDF

87.3 KB Created: 2021-08-19 21:08:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b72d8c73a5dc5930a0546ebaabe2cfb8 SHA-1: 723d565001a4cd943c62f826b9ad5de163a26e8c SHA-256: 88a67c7811f5542580014baa818d7ee147835f2739ed58808e6da8b44c9e4a09
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as a Pdf.Phishing.Trojan and flagged by an ML classifier with high confidence. It contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute malicious files. Although no scripts were explicitly extracted, the PDF structure and embedded URLs indicate a phishing or malware distribution attempt, likely leveraging embedded JavaScript for execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 7

  • 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.
  • 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 http://aranykoronakft.hu/userfiles/file/2108613543.pdf
    • https://ikitellirezistans.com/upload/files/denokafezugumeterikej.pdf
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/eab9455d010684a5f1ef34b047dcb7b4/36932515508.pdf
    • http://avs-market.ru/admin/ckfinder/userfiles/files/79910821110.pdf
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/806af7454ff4efb12ba83a151f586a4d/bexomesegivavu.pdf
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607ace4f6efdf---6108721383.pdf
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160ae0f441446c---66242751637.pdf
    • http://erfaspot.com/resimler/files/nonagilo.pdf
    • http://teleserviciomalaga.com/ckfinder/userfiles/files/76663385998.pdf
    • http://soles2walk.cz/data/file/seliperuzejuno.pdf
    • https://www.paseppe.gr/ckfinder/userfiles/files/xitorawafujijof.pdf
    • https://audreyheselmans.com/_files/file/50620170335.pdf
    • https://andrejc.si/files/file/vexirovarirepuvevifobi.pdf
    • https://syteq-pro.com/userfiles/file/10170188111.pdf
    • http://zaun-produzent.de/userfiles/file/tatelakapiburajesoxebo.pdf
    • https://abandassociates.com/ckfinder/userfiles/files/18747597272.pdf
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a38fedb4e66---rabigalex.pdf
    • http://luyenthitoeic.info/userfiles/file/kilupafedopunifiwixosomit.pdf
    • http://tccsrl.org/userfiles/files/fatabajugig.pdf
    • http://polletnv.be/uploads/files/dizavelukokibosilufobaz.pdf
    • https://brahmagnanam.org/fck_uploads/file/gosev.pdf
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc6ad921a36---lejumumo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=edexcel+as+level+chemistry+textbook+answers
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec7f.bin
2d61526fe8b52221d3f562f5f0ad983007f91c957e3c18a38902c41523d59f07
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC7F 18648 bytes
font_01_sfnt_off00011d94.bin
8e77ae5007d0235b9333a64100c3f1033140e04d05ace0eb3c81de36c40af913
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D94 11220 bytes
font_02_sfnt_off000137b6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x137B6 16792 bytes