Malicious PDF — malware analysis report

Static analysis result for SHA-256 81798f279bb67965…

MALICIOUS

PDF

81.3 KB Created: 2021-09-16 09:16:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 660c22211636f6d9afca9f9c627e003a SHA-1: af7674d6dd5258bdb52f275da5f803a21bdaa214 SHA-256: 81798f279bb67965133498f3f595de02d67ee124f9212472e3a9313bd545e8c1
134 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and ML classifiers indicated maliciousness. It contains numerous embedded URLs, many of which point to PDF files on potentially disposable hosting, suggesting a link farm or distribution mechanism. The presence of a 'download button' heuristic further supports a lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://hizlipin.com/calisma2/files/uploads/bizifadexisupuru.pdf In PDF document text
    • http://cheliabinsk.realxenon.ru/uploads/files/52941272418.pdfIn PDF document text
    • http://bc-arman.kz/ckfinder/userfiles/files/26215679480.pdfIn PDF document text
    • http://ebiocell.com/uploadfile/file///2021091209313570.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/161382a1167c30---5275964690.pdfIn PDF document text
    • http://www.adarshvidhyasankul.org/userfilesfile/movumowowejimibozip.pdfIn PDF document text
    • http://xn--jt2b56wn0ap2a.com/upload/file/202109071228282200.pdfIn PDF document text
    • https://pgprojekt.pl/Upload/file/buwebubopegizovum.pdfIn PDF document text
    • http://khautrangkhangviet.com/upload/img/files/sovorafujatot.pdfIn PDF document text
    • http://daimarconstrucciones.com/images/admin/file/mofam.pdfIn PDF document text
    • http://ginzaoakland.com/uploads/files/bukonatezubezubuditupima.pdfIn PDF document text
    • http://moscow-vernisage.com/files/files/95491596972.pdfIn PDF document text
    • http://aleshashop.net/uploaded_files/userfiles/files/42430210458.pdfIn PDF document text
    • http://aroma-es.site/yamituki-n/uploads/files/dulolusofuforiretizu.pdfIn PDF document text
    • https://ltssinternational.com/res/wysiwyg/file/69591462071.pdfIn PDF document text
    • http://polskienarty.pl/data/aktualnosci_imgs/file/tupugepenoja.pdfIn PDF document text
    • http://gizmakina.com/depo/sayfaresim/file/gugiziwusalasumarobodo.pdfIn PDF document text
    • http://metapolar.hu/tmp/65983705459.pdfIn PDF document text
    • http://client.diffuse.info/files/64920182517.pdfIn PDF document text
    • http://acutecardio.ru/sadm_files/bapifalutozudotofet.pdfIn PDF document text
    • http://superazs.ru/images/news/file/52822347939.pdfIn PDF document text
    • http://adhdesign.de/userContent/files/20210911195356-3330182927.pdfIn PDF document text
    • https://masterjobintl.com/ckfinder/userfiles/files/fukebiwajuxo.pdfIn PDF document text
    • http://bfttacg.marketsearching.com/upload/files/zikalep.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/e33170800eceeb99a35cf3f5cf51e3cf/41058557471.pdfIn PDF document text
    • http://digifast.cz/userfiles/migofegosusozebu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=wr3d+wwe+ultimodPDF 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_off0000d900.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD900 10328 bytes
SHA-256: aafa14a556206a32f3ac5a74761d514f9637d7979e7f86e413e3bcbe57f32a4e
font_01_sfnt_off0000f058.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF058 17984 bytes
SHA-256: e62c481199a0529c79da93532ec76b5525ff8e77f03d62966c2e038cbef40658
font_02_sfnt_off00011e5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E5A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1