Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae99c7300f810197…

MALICIOUS

PDF

81.6 KB Created: 2021-09-05 03:11:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 28e6c64329678a777b341b79b466a8d9 SHA-1: 80acfd0ec9f7633bea41dc1705bc48a4b4daeb30 SHA-256: ae99c7300f810197d4a67187071ad2e48d6939ab4d0804ddc4fd0f488f539f3b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan and by an ML classifier with high confidence. It contains numerous external URLs, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate a malicious intent to redirect users, likely as part of a phishing campaign or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://oniceh.ru/uplcv?utm_term=parts+of+body+worksheet+for+ukg PDF link annotation
    • http://myqself.com/upload/files/bakifaged.pdfIn PDF document text
    • http://keramann.ru/uploads/files/sojexax.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160963e72593e4---lezukirafum.pdfIn PDF document text
    • http://ex2010.com/uploadfile/file/2021080422235673499.pdfIn PDF document text
    • https://alternatifhirdavat.com/upload/ckfinder/files/26439917876.pdfIn PDF document text
    • http://clinicaveterinariamontecchia.com/userfiles/files/banisatogakiko.pdfIn PDF document text
    • https://awlights.com/wp-content/plugins/super-forms/uploads/php/files/f5a6e348027e01ca487bf97a53a9d688/tisij.pdfIn PDF document text
    • http://live-lessons.net/lcj/web/uploads/assets/file/19727797478.pdfIn PDF document text
    • http://traslochimontalto.it/userfiles/files/gosikuvebedejenodabe.pdfIn PDF document text
    • http://glenbrooksouth1970.com/clients/1/17/17fc1bd13d5538a69f39d58c869d2fc5/File/6057803670.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/754h52gq29gmv424gmr206tkg3/mubewiwe.pdfIn PDF document text
    • https://tp-pos.com/uploads/image/files/50663551625.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/xokes.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/f537f9ad3b05589f0676732c3133b095/8861251830.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/miwesoparulon.pdfIn PDF document text
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/27828156587.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/kixasobika.pdfIn PDF document text
    • http://airbaankhubon.com/userfiles/file/fonajadeja.pdfIn PDF document text
    • http://hugslock.com/app/webroot/img/files/67161434797.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd64730d5d9---72187188081.pdfIn PDF document text
    • https://hosvagyok.hu/userfiles/file/melivasuno.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/kuwelalilu.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_off0000dacf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDACF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E6 10924 bytes
SHA-256: 1c2d3b37f4d523fefff1edcc9fb16f3668e5e6a170beb9e3491be41567fba8a9
font_02_sfnt_off00010c4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C4A 17584 bytes
SHA-256: 7f68058c208b79eb1a2758d7788ced0e7cfac2c6baf67bd65fcc1e2644ed0274