Malicious PDF — malware analysis report

Static analysis result for SHA-256 9ead9d3bce270dae…

MALICIOUS

PDF

77.9 KB Created: 2021-09-10 18:43:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a8f0df1277433fe598e04d19e158c91b SHA-1: 19cd19206a69159073ad0be130bd9b8485284c71 SHA-256: 9ead9d3bce270dae3c0f1ee2e64935132232c373e07db7589e3f169dfb8152cc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains a link farm pointing to multiple PDF files hosted on various domains, several of which are associated with compromised CMS uploads. The presence of numerous links and the hosting on potentially compromised infrastructure strongly suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16134f633befea---puxezumizukonubuw.pdf In PDF document text
    • http://songdolandmarkcity.com/userfiles/file/lewatokakubofajopidomij.pdfIn PDF document text
    • https://trickapotisk.cz/webpagebuilder/ckfinder/userfiles/files/fedowipago.pdfIn PDF document text
    • https://preprodpcb.com/userfiles/files/71285913647.pdfIn PDF document text
    • https://cryptobasics.biz/uploads/files/lifanugidedakusirazazigiw.pdfIn PDF document text
    • http://burelomdo.com/ckfinder/userfiles/files/retowugizogiwig.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/84749663174.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/q2nh464fm561qgr1jfqth23daa/veziwagezakasafewetafev.pdfIn PDF document text
    • http://smeeing.com/userfiles/files/magedikixuzug.pdfIn PDF document text
    • http://travelbilet.ru/sites/default/files/file/notebitureviv.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/39566025795.pdfIn PDF document text
    • http://tiszaladany.hu/upload/file/24940916565.pdfIn PDF document text
    • http://neoneofytou.com/ckfinder/userfiles/files/42779212257.pdfIn PDF document text
    • https://www.cosanuesa.com/componentes/editor/ckfinder/userfiles/files/zabalibemitokoxale.pdfIn PDF document text
    • http://firewaterdamagedfw.com/test/fckeditor/uploadfiles/file/60369031748.pdfIn PDF document text
    • https://at1-turbo-j3t.com/contents/files/tulafigakerotiropasidokon.pdfIn PDF document text
    • http://vinhhangvien.com/upload/files/69268091264.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/951e1c2c6a183cd8483ec7d020884040/difopododabiderasubuzu.pdfIn PDF document text
    • http://toszegisuli.hu/userfiles/file/gozebarigezujizukenolaf.pdfIn PDF document text
    • http://polesprogettazioni.com/userfiles/files/sutunekaporevadin.pdfIn PDF document text
    • http://klawiatury-foliowe.pl/_data/file/8773466719.pdfIn PDF document text
    • https://lenaoyunlar.net/calisma2/files/uploads/46658030959.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1613133dfaed3e---51899622534.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=usb+device+not+recognized+android+studioPDF 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_off0000cb75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB75 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e387.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE387 17420 bytes
SHA-256: e310b5e3481b8eb2adf8b4a1f48e7b8119f157721afbb89a10455b64c8276c22
font_02_sfnt_off000110a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110A2 10872 bytes
SHA-256: 4a0b46664cfd9f130077fb9ac6005f518816c770ae3852a8b8fb5adc43c82f78