Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c9796b860af93ec…

MALICIOUS

PDF

82.6 KB Created: 2021-07-19 21:48:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 186a6cd3b233fb1cf38c7f873b114a01 SHA-1: e60d0aa7ea7b059c0509a05fe9ed91a430e81083 SHA-256: 4c9796b860af93ecd4b990c96f7956d1b5ef8ab67496529df08520f98553c817
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 a phishing trojan. The document contains a link farm pointing to numerous websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting an attempt to direct users to malicious content. No scripts were extracted, but the presence of numerous external links indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://birkhoffhi.com/userfiles/files/1667564792.pdf In PDF document text
    • http://atthaya.com/file_media/file_image/file/xuvoperitegipupivipam.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071ef6c85cd7---tifurezijeson.pdfIn PDF document text
    • http://kroonzuivel.nl/ckfinder/userfiles/files/baregarewavatomikafax.pdfIn PDF document text
    • https://nmg.lv/img/uploads/files/morixanusaf.pdfIn PDF document text
    • http://fireprovietnam.net/luutru/files/jekuki.pdfIn PDF document text
    • http://haiqi-machine.com/d/files/59182388800.pdfIn PDF document text
    • https://www.colours-of.com/wp-content/plugins/super-forms/uploads/php/files/67ntibngufuvg48i68kgpf9ti8/73969415688.pdfIn PDF document text
    • http://tiga.co.th/ckfinder/userfiles/files/271891890.pdfIn PDF document text
    • http://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a3d83a0f753---52978589466.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071ec1022c59---16926244566.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/paxade.pdfIn PDF document text
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/617j4ha3ru2issjg410akn3um4/84637038029.pdfIn PDF document text
    • http://dudikom.pl/userfiles/file/18882643410.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/34kume69v4kh0jdenalmd29cf9/44763240128.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a0d49fb9826---vebuvosogupux.pdfIn PDF document text
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/6dmm1tb3d546fhgngle2pcrfim/nixonorufab.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb207fd4ff9---64801117395.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/3b6cc42c3d522631edaf1331c43c9eaf/vavinuvarexusixude.pdfIn PDF document text
    • https://meganimal.pt/site/upload/file/kepiberu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=new+alvin+and+the+chipmunks+showPDF 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_off0000de1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE1D 17676 bytes
SHA-256: c6a32d6f94866c6cd4356e1b519a41a69dfcfb43de93196e9a355d5609853544
font_01_sfnt_off00010c87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C87 11000 bytes
SHA-256: 02d888dcfd742fc897c5f82c0e3a8c8d7af5702e05e61b89cd21a50889da9526
font_02_sfnt_off000125ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1