Malicious PDF — malware analysis report

Static analysis result for SHA-256 e704441e95d8d9d4…

MALICIOUS

PDF

83.4 KB Created: 2021-09-08 21:15:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 0ad1f3858132df1698eb32856b2fd578 SHA-1: f3a43db6717841938776989c0e19331f38ffbd93 SHA-256: e704441e95d8d9d4837d7d133f5343bdd8d453ad3b0df7c3fd87baed84cc2cad
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, suggesting it functions as a link farm to distribute further malicious content. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://coretry.ru/uplcv?utm_term=hong+kong+tram+map+pdf PDF link annotation
    • https://grupa-energia.pl/attachments/file/1490930186.pdfIn PDF document text
    • http://denkobarbell.com/_upload/files/8858773970.pdfIn PDF document text
    • http://sarica.com.tr/ckfinder/userfiles/files/gunapunazigif.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/a2ksvt3t1mtuuk0bc183fqdhg7/fipuzozodogip.pdfIn PDF document text
    • https://zzwgjx.com/d/files/39085104559.pdfIn PDF document text
    • http://neogmbh.de/www/sites/default/files/userfiles/file/13040264510.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/31093253856.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/24953038966.pdfIn PDF document text
    • http://gaongonmaiphuong.vn/webroot/img/files/28066521933.pdfIn PDF document text
    • http://tfforming.ru/d/files/rinodopajunurame.pdfIn PDF document text
    • http://oresteruggiero.com/userfiles/files/88071491662.pdfIn PDF document text
    • https://b2b-intelligence.it/uploads/file/34071952209.pdfIn PDF document text
    • http://group-anons.ru/userfiles/files/62675267223.pdfIn PDF document text
    • http://normel.org/files/upload/file/tosagusinuganidofume.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/4081b51b0e5a4e4dcb57daea41231df2/62263534819.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161375175e1c86---5534329979.pdfIn PDF document text
    • http://traiteurluc.com/userfiles/file/69682371185.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/161351b1b1347a---96995618874.pdfIn PDF document text
    • https://stayinbranson.com/ckfinder/triplebuserfiles/file/popofa.pdfIn PDF document text
    • http://poaglasses.com/uploads/files/202109081015465708.pdfIn PDF document text
    • https://dienhoanghean.com/upload/ck/files/5972227430.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/78069650178.pdfIn 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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9FF 10488 bytes
SHA-256: 8b930373fba7eabf02ee75ed8619311855a895fddb61fd16552e6c82268b952a
font_02_sfnt_off00011193.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11193 17988 bytes
SHA-256: 4ca6f1574489f75d6aab9cb01d5ed0dfed9e21cc5cd1693b41ff0d4f12b7d447