Malicious PDF — malware analysis report

Static analysis result for SHA-256 503d7a4193105854…

MALICIOUS

PDF

89.0 KB Created: 2021-08-22 00:12:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 2a560a2fe300221aceb708241ad12195 SHA-1: b78d1555aec34cb53730da87aece7bba6be8b82c SHA-256: 503d7a4193105854eb103e34509791777040cbb21914e18131ac021353b7ab6f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous links to external PDFs hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a pattern of using compromised web infrastructure for hosting malicious content. No scripts were extracted, but the overall structure and URL findings point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://canhtoanland.com/upload/files/mipenesosa.pdf In PDF document text
    • http://amandatravel.com/userfiles/file/70881128389.pdfIn PDF document text
    • http://koopmankennedyfeller.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/97179833548.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/7409563306.pdfIn PDF document text
    • http://apcmagon.com/userfiles/xegenamu.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c64e6d0b09---rutuzajuvititigaba.pdfIn PDF document text
    • http://orhs76reunion.com/clients/30721/File/lunenagobenineraviz.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/423f07f0962db4e8113661718adb4ba0/39243971370.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab15dd8c6ae---52069887245.pdfIn PDF document text
    • https://fokusmedia.com/images/uploads/litokakawuj.pdfIn PDF document text
    • https://www.icslights.com/wp-content/plugins/super-forms/uploads/php/files/8028c708eb34897176789f24c383b371/wolofowewononurogesowon.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607a41d766d09---22687816115.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/6570f74b28ea87721f4c1e5bfcac7287/zodixoza.pdfIn PDF document text
    • http://cec-intl.ru/app/webroot/files/file/bujidirimiwuxoteko.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/16083f507133a6---24411703566.pdfIn PDF document text
    • https://samarpanbharat.org/trila/userfiles/file/nanazagowubelowupigepubu.pdfIn PDF document text
    • https://uniqrelation.com/userfiles/file/nidituwavafogataxen.pdfIn PDF document text
    • http://paradisetourkorea.com/FileData/ckfinder/files/20210605_F828B2997C4F346E.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/90072078592.pdfIn PDF document text
    • http://inciboya.com/resimler/site/files/14549475182.pdfIn PDF document text
    • https://2acontractor.it/images/file/rebexuvefo.pdfIn PDF document text
    • http://natur-pet.cz/webpagebuilder/ckfinder/userfiles/files/42424720063.pdfIn PDF document text
    • http://stellar.ru/ckfinder/userfiles/files/81348439933.pdfIn PDF document text
    • http://casier-a-bouteilles.fr/file/20890799767.pdfIn PDF document text
    • http://syarmarka.ru/userfiles/files/gudaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=a+wrinkle+in+time+chapter+3+questions+and+answers+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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f3f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F0 11460 bytes
SHA-256: c34eb634348b108ce8d729e2f56e39d4e7771a74528734b08ff232f3e4a354c3
font_01_sfnt_off00010eb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EB8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000126ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126CA 17380 bytes
SHA-256: 7e8a0af475e1b979b7753c0567e51a6590537936d70beb27a98a95ba99c47011