Malicious PDF — malware analysis report

Static analysis result for SHA-256 44661d2c3d7782c2…

MALICIOUS

PDF

79.0 KB Created: 2021-09-20 03:36:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4c3c43fcbde97ed5b4cd900373410a11 SHA-1: 24090b9fa27ce18112a1a9505270436fa78d9f9d SHA-256: 44661d2c3d7782c2db3be4e0b449615ed8e46f82a3e03804b1830bc12167803a
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs, many pointing to disposable hosting or compromised CMS uploads, indicate a link farm designed to redirect users to potentially malicious content. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 http://xn--80ahcjevtqq.xn--p1ai/ckfinder/userfiles/files/sokugelivukezovited.pdf In PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161405f7c0edf3---86671405038.pdfIn PDF document text
    • http://imdmotors.com/uploadfile/file/2021091612371399.pdfIn PDF document text
    • https://hotellemaritime.com/hotel/upload/files/wibobusul.pdfIn PDF document text
    • http://danieldesignpro.com/userfiles/bepazijulot.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/a9iijs909o3fd8gsouh5bkabis/62706984417.pdfIn PDF document text
    • http://fitsiluet.cz/data/file/zusovoliwaxabir.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/bjspl74kunpoo5he5mv4iqo4v0/panelomikemoloparamu.pdfIn PDF document text
    • http://pravkniga.ru/files/userfiles/files/26764570759.pdfIn PDF document text
    • http://3gr-group.com/ci/userfiles/files/70575819255.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/gijuw.pdfIn PDF document text
    • http://the100voicesofgospel.ch/fichiers/newsletter/file/gafobivewubewomazo.pdfIn PDF document text
    • http://villabrown.it/userfiles/files/91004394080.pdfIn PDF document text
    • http://splhardware.com/UploadFile/file/2021090208494073499.pdfIn PDF document text
    • https://tedvandergulik.nl/userimages/file/68778748088.pdfIn PDF document text
    • http://security-m.jp/tool/images/file/41278864798.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130121e20bfe---43833443388.pdfIn PDF document text
    • https://tapuionoticias.com/ckfinder/files/jexagazodiriwi.pdfIn PDF document text
    • http://worldcar.jp/userfiles/files/66074427487.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/fq9tse7ti1hlh2k666tj4m0ovm/jifajijawagigoja.pdfIn PDF document text
    • http://ore-processing.ru/d/files/91344442427.pdfIn PDF document text
    • http://trevelsi.ru/ckfinder/userfiles/files/51310419604.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=old+version+skype+for+androidPDF link annotation
    • http://zs.tom.ru/jsplugins/ckfinder/userfiles/files/toretaxufum.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_off0000d07e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD07E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e895.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE895 10688 bytes
SHA-256: 8abe17e0b33f34ee42daf3e3af68979d2f5b7f00120105e4d6db02adfe497943
font_02_sfnt_off00010132.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10132 17688 bytes
SHA-256: d9d755151bfef3cf6beb332f98c39f378d05c8281e47e0e9cc5806c78c95493b