Malicious PDF — malware analysis report

Static analysis result for SHA-256 31cf8d40789c3e20…

MALICIOUS

PDF

77.7 KB Created: 2021-09-19 21:30:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1b7b095b35a587e001cb2c5e9bd4c873 SHA-1: 9ccec57fecec364ab732c396f73957f5db8a3314 SHA-256: 31cf8d40789c3e203cf20e97ef77b6911e3743ae5d868a74676a5ee1f4329c81
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised websites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of external URIs and link farms points towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://litho-and-co.fr/ckeditor/upload/files/68257914315.pdf In PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6c8b8fc2965bd91b1611aa1f295e3ba3/64043393280.pdfIn PDF document text
    • http://miyozenemeryville.com/uploads/files/nigadurisoj.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/4897449514.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/naxidezodi.pdfIn PDF document text
    • http://www.pavimentosyreformasferlu.es/ckfinder/userfiles/files/lifituduruzuvil.pdfIn PDF document text
    • http://dvg.asia/ckfinder/uploadfiles/files/38619351242.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/829516a80ed0641350c17c2638cc9d54/87573815139.pdfIn PDF document text
    • http://topbondtape.com/uploadss/file/regujiwiv.pdfIn PDF document text
    • http://thueotodn.com/uploads/image/files/kivagixajapisoxojawikiva.pdfIn PDF document text
    • https://sporyolu.com/resimler/files/tukorusiradojo.pdfIn PDF document text
    • http://lncxjzxxw.com/upload_fck/file/2021-9-5/20210905191020712953.pdfIn PDF document text
    • https://ceiling.holcom.vn/webroot/img/files/59717972426.pdfIn PDF document text
    • http://jfhconsultancy.nl/userfiles/files/sufagasozoxe.pdfIn PDF document text
    • http://gidromall.ru/img/uploads/file/xokiv.pdfIn PDF document text
    • https://tradingcall.in/ckfinder/userfiles/files/81276135452.pdfIn PDF document text
    • http://t-eamplus.de/web/editor/files/15160488411.pdfIn PDF document text
    • http://nm-union.ru/ckfinder/userfiles/files/patudikokefipowerel.pdfIn PDF document text
    • https://whatshoulditcostme.com/userfiles/file/76114054036.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c39db3db0f---19479128407.pdfIn PDF document text
    • https://rpdev.org/ckfinder/userfiles/files/29999034325.pdfIn PDF document text
    • http://pngroup.pl/ckfinder/userfiles/files/powopidezelapeninafira.pdfIn PDF document text
    • http://dailynewsodia.com/assets/ckfinder/core/connector/php/uploads/files/89681359245.pdfIn PDF document text
    • http://napiarsaigh.com/images/rojegonisov.pdfIn PDF document text
    • http://njbeihang.com/uploadfile/file///2021090222070872.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=free+minecraft+java+edition+account+generatorPDF 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_off0000c967.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC967 17872 bytes
SHA-256: b182cf89f7d4930984c77bcea4cd6c606c2ac6149a569e2fdbe904ab4a1d28ca
font_01_sfnt_off0000f7e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ffb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FFB 10880 bytes
SHA-256: bc334bb15bd18fbf547b891d54274fbc0fd2729ea698917c355e499ebfb16cf1