Malicious PDF — malware analysis report

Static analysis result for SHA-256 72832cdb074ed178…

MALICIOUS

PDF

78.0 KB Created: 2021-09-15 18:29:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: fd9b23534b1afe7c476c5d45a00ba809 SHA-1: c357b8ed03fbdbe944901fa2e7fad117ae439daf SHA-256: 72832cdb074ed17889d6ed24c4bfac1f8498f8c402150a7230dff05e42fc2cf1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, forming a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 https://coretry.ru/uplcv?utm_term=doctor+who+classic PDF link annotation
    • http://pwr-tech.ru/userfiles/file/tuxeropazixin.pdfIn PDF document text
    • http://orchid-daikanyama.com/userfiles/file/butoriwifafalopon.pdfIn PDF document text
    • http://cudicio.it/images/file/vivumeran.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/90536714553.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/3e7b2b54db2782951561a1a836b02739/gesatukezababujidumomudep.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137f9973627f---renidate.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b7dd902836---wojazadebuzitifode.pdfIn PDF document text
    • http://gzperson.com/uploadfile/files/9268697083.pdfIn PDF document text
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/99357798057.pdfIn PDF document text
    • http://avandcie-automation.fr/ckfinder/userfiles/files/51866129105.pdfIn PDF document text
    • https://gikguamerica.com/userfiles/file/61479322929.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/livadozukuxuxib.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/venajum.pdfIn PDF document text
    • https://cs168.tw/upfiles/editor/files/xuvokig.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/lfhv5qsfoco97shmi3842ni6t5/3885119698.pdfIn PDF document text
    • https://yapluka-services.fr/userfiles/file/palanatu.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/og6rdon9ol074rek5tmkfn6ci2/xafejavare.pdfIn PDF document text
    • https://mchs.kz/userfiles/File/tabogubobipinobavom.pdfIn PDF document text
    • https://hinaweb.com/upload/file/kaduvedutibataniguj.pdfIn PDF document text
    • http://vp-dmsh.ru/admin/ckfinder/userfiles/files/54776150682.pdfIn PDF document text
    • https://hunglivet.com/uploads/files/202109020636457437.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_off0000cdc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDC8 10176 bytes
SHA-256: d18dbf1e8758a673f7ebed0531dd2a785b8ca96717dbc9d15f41cd2fd4e1d35d
font_01_sfnt_off0000e4bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4BC 17644 bytes
SHA-256: 95060a9456a22b0b8c262cf22fd4ce6faad121fbdb3140c8df25cd777aa2e278
font_02_sfnt_off000112ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1