Malicious PDF — malware analysis report

Static analysis result for SHA-256 d7825fdb4b24737a…

MALICIOUS

PDF

70.2 KB Created: 2021-09-29 02:44:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: d38cdef98a71c1534fee30fd359bbca6 SHA-1: 9dd79baa2c756b703681349d7986167cdf220b6e SHA-256: d7825fdb4b24737af4e6412000a9048e65aa850433589b3544f49b60cf0451e4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous embedded URLs pointing to other PDF files hosted on various domains. The primary purpose appears to be SEO manipulation or distributing further malicious content through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://grupafurman.pl/!mag2011/userfiles/file/26398796579.pdf In PDF document text
    • http://kdwatch.net/upload/files/2021091713432835.pdfIn PDF document text
    • http://chineseclothingonline.net/File/folipukosaremosan.pdfIn PDF document text
    • http://www.polni.si/Images/files/lukaxiwegifakox.pdfIn PDF document text
    • https://chowdhurytourism.com/ckfinder/userfiles/files/50277029631.pdfIn PDF document text
    • http://wawa757.com/uploads/files/63198333812.pdfIn PDF document text
    • https://togelunited4d.com/contents/files/14215580160.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/11840199063.pdfIn PDF document text
    • https://truckforceone.com/upload/editor/file/23428498299.pdfIn PDF document text
    • http://mikomisushiwc.com/uploads/files/vokuxaxulunusuvemajujuti.pdfIn PDF document text
    • http://tsyrulnikov.ru/upload/file/rotogafudumukawisor.pdfIn PDF document text
    • https://dienlanhhonganh.com/images/pic/file/nirewopav.pdfIn PDF document text
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/piliviz.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/83138659184.pdfIn PDF document text
    • http://inbeeldt.nl/userfiles/file/82503962035.pdfIn PDF document text
    • http://xn--o79av69abka850ab6c.com/upload/file/202109210622008887.pdfIn PDF document text
    • https://biorenta.lt/ckfinder/userfiles/files/runevasakuwonigalexofa.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/lgo71cbtjsmkr8b5jcqth6p4kr/97635889492.pdfIn PDF document text
    • https://hnhaa.com/userfiles/tnejp/files/18592171409.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/1d8449176803f8654d9ad252f15b73eb/75088214075.pdfIn PDF document text
    • http://skupka54.ru/upload/m/kifebalako.pdfIn PDF document text
    • https://gtijsr.com/userfiles/file/9816081118.pdfIn PDF document text
    • https://tezerwatch.com/file/upload/files/09-01-18-17-40-24.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+enable+usb+debugging+on+android+using+cmdPDF 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_off0000aeae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEAE 11028 bytes
SHA-256: 6c8da4b088b4d86cb86fcb4c52ebd2c3e91762140addf0ec583da7d1022e8469
font_01_sfnt_off0000c822.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC822 16124 bytes
SHA-256: ed838b66bfab3abd371f124b9c0f9b39206ff155cbd1f2fad1c56b9251211428
font_02_sfnt_off0000f0e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1