Malicious PDF — malware analysis report

Static analysis result for SHA-256 cec8bad5c983ab57…

MALICIOUS

PDF

84.7 KB Created: 2021-09-19 07:31:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e1a0bdbfd987198e62b3570547427b1c SHA-1: d8d2f708bf6b37876608ee482dc9a75da5630ff0 SHA-256: cec8bad5c983ab57d0d8e5435ab4a60b221f7e734f294a3015f6772cc19f48c9
192 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and multiple external URIs, many of which point to potentially compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest a malicious intent to host and distribute further payloads. The ML classifier and ClamAV detection confirm the malicious nature of the file, likely serving as a downloader for a second-stage exploit or malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 9

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://quimis.org/js/ckfinder/userfiles/files/gatovazisosi.pdf In PDF document text
    • http://heorungminhphat.com/luutru/files/68509727073.pdfIn PDF document text
    • https://imihwa.com/uploads/image/20210919/files/20210919083105.pdfIn PDF document text
    • http://xinshifm.com/userfiles/file/kavamizupuvo.pdfIn PDF document text
    • http://crmrealty360degree.in/userfiles/file/75755335608.pdfIn PDF document text
    • https://roofmed.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161339740347fe---zobedax.pdfIn PDF document text
    • https://poojaindiangrill.com/nbloom/fckuploads/file/vasewarakeduxek.pdfIn PDF document text
    • http://thriftstorewebsites.net/flash/thriftstorewebsites.net/file/rukugefe.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1907ba609---xosoroxajavimapogunadiz.pdfIn PDF document text
    • http://5thaveseniors.org/userfiles/file/9791737902.pdfIn PDF document text
    • http://xtra360.net/campannas/file/xopawetu.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/waruxoxobutipukowo.pdfIn PDF document text
    • https://beysukonaklari.com/ckfinder/userfiles/files/jojaja.pdfIn PDF document text
    • http://dasbluemchen.com/78481188565.pdfIn PDF document text
    • https://absoluteanytime.com/media_file/files/files/xazure.pdfIn PDF document text
    • http://mkngsp.ru/upload/files/roxuwibebababinamuluni.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/202199657521627.pdfIn PDF document text
    • http://bjsddesign.com/filespath/files/20210909163458.pdfIn PDF document text
    • http://naphotelbangkok.com/userfiles/files/94319232500.pdfIn PDF document text
    • https://nhahangphongcanh.com/uploads/files/24979909664.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16132cd78248ae---6774695203.pdfIn PDF document text
    • http://playoz.com/ckfinder/userfiles/files/64850417708.pdfIn PDF document text
    • http://volkshilfe-vlbg.at/images/content/files/75852931923.pdfIn PDF document text
    • https://drticket.ir/basefile/drtiketcom/files/65532621900.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/3r71rccm5h9h8seefmhavqmc1kdog2ga/48129481710.pdfIn PDF document text
    • https://cleanenergy.mn/uploads/files/rakoxexawav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=the+official+guide+to+pte+academic+pdf+free+downloadPDF 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_off0000e6c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6C5 11048 bytes
SHA-256: 3f6ff60905074ceb6e7103192e67c75d3511ffc4b1b4ecea292d94cfc1f1c6d7
font_01_sfnt_off00010029.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10029 17036 bytes
SHA-256: 5f888442e5cb3a15c21298a79293b1b4a1949c7bda7c0ebe90c35e5e2fd0e9e7
font_02_sfnt_off00012c23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C23 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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