Malicious PDF — malware analysis report

Static analysis result for SHA-256 23ef9a03d0ec8f98…

MALICIOUS

PDF

88.2 KB Created: 2021-07-04 06:36:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 18dfe39ba743604ccce971cfd92a9e58 SHA-1: 133fe38738c96426e41780a464d5de0d79cabdf2 SHA-256: 23ef9a03d0ec8f9892851a887218b5d53e56f520cdcab7f8886dff3bee124344
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with many embedded URLs pointing to compromised WordPress uploads and other potentially untrusted domains. The primary purpose appears to be directing users to external, potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/88d9526de0c79e7a18628e83a0cfa73b/74530313648.pdf
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f4d44b0cc9---69659308199.pdf
    • http://poorclarescork.ie/images/gusazazap.pdf
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160850b6640c72---62627960898.pdf
    • http://shinies.ru/img/lib/file/dagad.pdf
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab73fab3b77---woxafo.pdf
    • http://call.ae/wp-content/plugins/formcraft/file-upload/server/content/files/1606f00037d65d---bibusijegisisirukilin.pdf
    • https://www.treehousecare.org/wp-content/plugins/formcraft/file-upload/server/content/files/16079985863ab5---33752413906.pdf
    • https://syteq-pro.com/userfiles/file/nenufugamopapekid.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/51l4jipcp0jeaphlc9lreuvoe0/2957950979.pdf
    • http://cs-web-design.de/ablage/userfiles/files/46951029868.pdf
    • http://vitaminyplus.eu/files/file/xizibulixorofoluzajagazu.pdf
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/cvkvf7ckg6b65pjpau4t5nm1oa/tiwiroxameg.pdf
    • http://haai.org/upload/file/89295344923.pdf
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/u6c8eujlnf1o9akg13bjjla1ht/tozurujudavedazab.pdf
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/ee4t0shm8dpsho9k4nfo8a79vd/51232139664.pdf
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/lrh1hkeqk99vf66adimsdhec7l/13593155064.pdf
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cf8657e248---80664906793.pdf
    • http://promador.pl/userfiles/file/wetataj.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a178133220c---79948298717.pdf
    • http://campbellelectronics.com/uploads/91344493734.pdf
    • https://c4ir.ae/wp-content/plugins/super-forms/uploads/php/files/ruqta6262q0a4tiut6chqn3co4/67406210745.pdf
    • http://ahxxzx.com/userfiles/202105/file/tikuwimexipawilulale.pdf
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/vikutijo.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=if+your+eye+is+red+what+does+it+mean
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f4cd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4CD 16792 bytes
font_01_sfnt_off00010cdf.bin
5e17e5049e66142a73cec200208420d00833ac543cac6df341402772c4196b7b
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CDF 17364 bytes
font_02_sfnt_off00013aaa.bin
460d68c08bf5d9bba9fd4a84d509162bca4895fa9749c1f16f6246f575b4ddbe
pdf-font-stream PDF embedded font (sfnt) at offset 0x13AAA 10824 bytes