Malicious PDF — malware analysis report

Static analysis result for SHA-256 73c1667df2b6c9b6…

MALICIOUS

PDF

69.8 KB Created: 2021-09-27 12:32:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ab35ada4f0bdb9cc1a352dcf3641fdf9 SHA-1: 90da0a3c3d25b4b1a5694d5a5790fe0832608289 SHA-256: 73c1667df2b6c9b6ed1c033aabe96574922581a7cc4fd02f043c5168f78d7abe
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs structured as a link farm, with several pointing to compromised CMS upload directories, suggesting an attempt to distribute or host malicious content. The presence of these links and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly indicate a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://crewmak.ru/uplcv?utm_term=the+sims+freeplay+android+hack PDF link annotation
    • http://robwalker.net/fckupload/file/37999982982.pdfIn PDF document text
    • https://sieuthimaytinhcu.vn/upload/files/50348771685.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/1554283a6ac5849ed4daade86a419861/11211430994.pdfIn PDF document text
    • https://univerosg.com/ckfinder/userfiles/files/27373745867.pdfIn PDF document text
    • http://4darchitecture.org/img/all/rafiga.pdfIn PDF document text
    • https://bitree.com/ckfinder/userfiles/files/39424567832.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d4aa4b1435---58696026481.pdfIn PDF document text
    • http://navrattan.co/userfiles/file/81095444875.pdfIn PDF document text
    • http://timebymtm.com/upload/files/1947999931.pdfIn PDF document text
    • http://bluebiz.kr/userData/board/file/sosoxan.pdfIn PDF document text
    • http://kristiankutschera.de/userfiles/file/43786721170.pdfIn PDF document text
    • https://talenthunt.biz/userfiles/file/diwadegobegedak.pdfIn PDF document text
    • http://k2plusinterior.com/userfiles/jadiragipir.pdfIn PDF document text
    • http://hosungtour.net/FileData/ckfinder/files/20210925_304C2ACD7BAEE725.pdfIn PDF document text
    • http://speaklifeiamgreatness.com/files/files/59403281201.pdfIn PDF document text
    • http://vinhthuan.vn/upload/files/87238344651.pdfIn PDF document text
    • https://onutglen.com/caningest/images/file/59848246290.pdfIn PDF document text
    • https://khoahoc.timviec365.com/picturesfiles/kesizukomagexixipotedoloj.pdfIn PDF document text
    • https://catwalkdogcome.com/editor_upload_image/file/vibotenufilax.pdfIn PDF document text
    • http://ipea.kr/userData/board/file/todirigi.pdfIn PDF document text
    • http://nsmpublicschool.org/slbdavbatala/userfiles/file/kevulipisikexotafefuwod.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/4k0k0eqqhcjkp4q9e84roa2s8o/97098192768.pdfIn PDF document text
    • https://ra7a7p-h3ba7.com/contents/files/47943505637.pdfIn PDF document text
    • http://nokianhakkablue.ru/ckfinder/userfiles/files/siniwix.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_off0000b2b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2B1 10956 bytes
SHA-256: 9c0f86c68705d0c57df9e84f20ec398a8e6ca1cbc0ed7a47a6f137fb5ed4c380
font_01_sfnt_off0000cbea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBEA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e3fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3FC 14896 bytes
SHA-256: 4ec9b9a7be8580263d2b1994f8807c6749ce9ad22a9982e1e61f8b5df93ed975