Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4404842b915edb2…

MALICIOUS

PDF

76.6 KB Created: 2021-11-12 21:38:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 56a8f30a90c2c2a45ae5d417362d7298 SHA-1: 7e04eca997644422b2fee8b4d4e0398d52d5604a SHA-256: b4404842b915edb2ce4e3c8c79bf5bd42ae516c7215d267f7b28478db840419b
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable hosting, suggesting a link farm or phishing lure. The PDF structure and embedded links point towards an attempt to redirect users to malicious sites, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/16158031490f2e---wenaruzerubirarisowin.pdf In PDF document text
    • https://iuoshili.com/upload/users/files/jopamoripofa.pdfIn PDF document text
    • https://www.psk.com.au/application/third_party/ckfinder/userfiles/files/kujulirogoxeniwur.pdfIn PDF document text
    • http://www.fred-robin.com/ckfinder/userfiles/files/76286305262.pdfIn PDF document text
    • https://cplastik.cz/data/cms/file/4510110649.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/foxenesokawupema.pdfIn PDF document text
    • https://ilexgold.com/app/webroot/files/userfiles/files/zokogifowopenugomiwavino.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f05380484---dutarefigufareti.pdfIn PDF document text
    • http://cnkls.com/userfiles/file/1636280738.pdfIn PDF document text
    • http://diversecityuk.com/userfiles/file/45332496571.pdfIn PDF document text
    • https://al-wesam.com/userfiles/files/vopukubiwopexinotud.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1618b0e323c656---pumixugerusenuxasapikiv.pdfIn PDF document text
    • https://mannoorpally.com/uploads/file/xakagejad.pdfIn PDF document text
    • http://ansonseatery.com/uploads/files/maluwutafopobirurugojowog.pdfIn PDF document text
    • https://sandp-engineering.com/ckfinder/userfiles/files/xotebirudepijanete.pdfIn PDF document text
    • https://www.aspart.ro/ckfinder/userfiles/files/ruzaguzileto.pdfIn PDF document text
    • http://goodtraefarm.com/ckupload/files/xuwubifezodamutebe.pdfIn PDF document text
    • https://zooiguana.pl/app/webroot/media/files/tepobituf.pdfIn PDF document text
    • http://rothemtour.com/FileData/ckfinder/files/20211015_6AEA3B3E5B4C4F03.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/1902d50e71a6c6a031117066e0548fb1/kewalugid.pdfIn PDF document text
    • https://dsverano.com/UserFiles/File/5390855148.pdfIn PDF document text
    • http://xn--h1acbpobggs.xn--p1ai/data/files/3052991418.pdfIn PDF document text
    • https://profm.hu/files/file/jajanokudugo.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/0d0af39f026c16a292e161156ddc2d45/920755859.pdfIn PDF document text
    • https://kangaroovietuc.vn/webroot/img/files/pefaxekof.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/vItLtdF7Pec/uplcv?utm_term=the+first+noel+piano+sheet+music+pdfPDF 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_off0000c4de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4DE 16540 bytes
SHA-256: 45015263e28dbf00792e0fa83ae0fb9123af5110209f191c00797c49350166ef
font_01_sfnt_off0000dc04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC04 10948 bytes
SHA-256: a052a35314fb45d759b49f5fc4dd2d9dfc1415b04beef3b3c5bf1854648db921
font_02_sfnt_off0000f537.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF537 17900 bytes
SHA-256: 920804c01ef9694a28eeaed78a57556ada8beb95c6602ad182e16551bd8d211e