Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf4be6081dac3f3e…

MALICIOUS

PDF

89.9 KB Created: 2021-09-16 02:49:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 376079fa0d0744b7358167e040fd7290 SHA-1: 6331405c15b8714896c908dbf05a76ce83f99ac9 SHA-256: cf4be6081dac3f3ee398b9478e30cd471608704379e04b4f5e1529940d266632
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous other PDF files hosted on disposable domains. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the link farm suggest an attempt to redirect users to malicious content, likely for phishing or scam purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

Heuristics 5

  • 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.
  • 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://zussobrance.sk/grafika/dokumenty/4684653713.pdf In PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c02ed38daa---43014897863.pdfIn PDF document text
    • http://smartpaintingplus.com/userfiles/files/93403237477.pdfIn PDF document text
    • https://flyags.com/editorResources/file///48992495906.pdfIn PDF document text
    • https://8foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/tafazexo.pdfIn PDF document text
    • https://sentralperdana.com/file/46073755744.pdfIn PDF document text
    • http://2990592.ru/ckfinder/userfiles/files/zumad.pdfIn PDF document text
    • https://jasmijnbloemengroen.nl/userfiles/file/dafunojezizulejiso.pdfIn PDF document text
    • http://kbo.pl/ckfinder/userfiles/files/juxabunesevugero.pdfIn PDF document text
    • http://parfumland.sk/upl/75079239964.pdfIn PDF document text
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/64851949158.pdfIn PDF document text
    • http://foodchemsino.com/d/files/55093180274.pdfIn PDF document text
    • http://adice-area.com/pictures/files/7552399106.pdfIn PDF document text
    • https://theipbuzz.com/images/file/ruzajibijawipesevo.pdfIn PDF document text
    • http://gartenbaukoeln.de/uploads/files/28804735470.pdfIn PDF document text
    • http://ruizhishengwu.com/uploadfiles/file/132114074569.pdfIn PDF document text
    • https://rachelrom.com/rescontent/file/19334366650.pdfIn PDF document text
    • http://vuoncotichdep.com/upload/files/93274394824.pdfIn PDF document text
    • http://oldadmin.k12cart.com/media/files/30760439740.pdfIn PDF document text
    • https://www.sexualaufklaerung-schule.ch/ck/ckfinder/userfiles/files/jufaxogiwevugudali.pdfIn PDF document text
    • http://meghdoothsuzuki.com/uploads/35266955332.pdfIn PDF document text
    • http://9262895.ru/ckfinder/userfiles/files/vateranugelowu.pdfIn PDF document text
    • http://opsir.eu/files/file/80194890924.pdfIn PDF document text
    • http://namadagaskare.ru/ckfinder/userfiles/files/momifomovigedukusabute.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=1+maze+runnerPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_006_off000140d2.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x140D2 16888 bytes
SHA-256: 65ec3de44c6767b8e65203987ef3fdcb051680f0a6e754af9a448a5e13c569ec
font_00_sfnt_off0000d619.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD619 24452 bytes
SHA-256: 11514383c044988ce768cc8cc7b2cca6b4174bdce61b722c78f866e9ff1450aa
font_01_sfnt_off00011322.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11322 9860 bytes
SHA-256: ed142dc76b67b56a3ace6c9ab0fbf9b2d537389d8d925da0db0dec1d3d0d6175
font_02_sfnt_off000128c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1