Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c2fef4122b96437…

MALICIOUS

PDF

80.0 KB Created: 2021-10-11 02:53:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: f286d3cdbeb29c3a0f1b659a9d520a00 SHA-1: 98f3c5f5564d1c5fe5949c7d5ee65114bad0e786 SHA-256: 8c2fef4122b96437b66cffbc4a3d8e5f832005c3d2dde6843e90447a07c906bc
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution intent. It functions as a link farm, containing numerous URLs pointing to compromised websites, likely to lure users into clicking malicious links. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://sinoscaform.com/upload/ckimg/files/202109120855326597.pdf In PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/2073ceec679559652f7d677946ad3589/99101732196.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/namemuluxerakatagubegoz.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/2sf9nkvkc2e4atbkbku82lpjk1/kemosepusasukuked.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-15/20210915222836950586.pdfIn PDF document text
    • http://vitalbafitnessclub.eu/userfiles/files/vuwikufukozaze.pdfIn PDF document text
    • https://sjamsul-hidajat.id/ck_uploads/uploads/files/25935735895.pdfIn PDF document text
    • http://uitvaartverzorgingsindex.nl/images/uploads/32643819941.pdfIn PDF document text
    • http://760_709737661.mildmedia-dev.eu/uploads/userfiles/files/43253200204.pdfIn PDF document text
    • http://chinalanpa.com/images/upload/File/65694957210.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1633059081.pdfIn PDF document text
    • http://shuimotongyuan.com/userfiles/file/fofelexoxaz.pdfIn PDF document text
    • http://staropolski.net/Upload/file/lejojevufoxid.pdfIn PDF document text
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/basapelogazibawutujapoda.pdfIn PDF document text
    • http://amandamaitland.com/images/file/boxolipa.pdfIn PDF document text
    • http://legalinet.eu/userfiles/files/86109681471.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/t6lcqmr9pgr0s3jjesj65jpjs1/49717774704.pdfIn PDF document text
    • http://hilimall.ae/uploads/files/23481316322.pdfIn PDF document text
    • https://pagodatalk.com/_UploadFile/Images/file/nobexitol.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161524bc751346---19384929282.pdfIn PDF document text
    • https://nsaimmigration.com/userfiles/file/84572452036.pdfIn PDF document text
    • https://brillimet.com/uploads/files/202109201017237615.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=sc+joint+painPDF 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_off0000d3f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3F5 10124 bytes
SHA-256: 45e4e55285f0b1c584893610f09332f01a84caff6a8382882cf63e8c303879e8
font_01_sfnt_off0000eaab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAAB 18428 bytes
SHA-256: f355026ddfec8500ae8de8ac55c8d029ae63bfce12ed5cf8300011fb92ac249a
font_02_sfnt_off00011a91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A91 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1