Malicious PDF — malware analysis report

Static analysis result for SHA-256 10b9c5d2f91546b7…

MALICIOUS

PDF

75.4 KB Created: 2021-09-03 17:46:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 66917d559e06e3ab586d732348a4a02c SHA-1: 9e1b97425aab8ce567b926a5651db3050e78ba8b SHA-256: 10b9c5d2f91546b78a1c7133561eeb8f7b2b314909929923f34074c91d6b3008
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple external URIs and link farm heuristics points towards an attempt to lure users to external, potentially harmful, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://digemnd.com/UserFiles/file/20146720849.pdf
    • http://maivietnamesecotati.com/uploads/files/54742733092.pdf
    • http://www.anieliasfx.com/uploads/textareas/file/89126036022.pdf
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16089ddfdf0504---37449985472.pdf
    • http://sgrappresentanze.eu/userfiles/files/46514257867.pdf
    • http://nuraski.pl/wsg/userfiles/bawanodarofugokabukubikak.pdf
    • http://agataklimowska.pl/userfiles/file/litutepumax.pdf
    • http://pincailight.com/zk/UploadFile/file/2021071702500073499.pdf
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16079a78816804---98749972490.pdf
    • https://universal4shipping.net/userfiles/file/511725308.pdf
    • http://msiutilities.biz/documents/21445191834.pdf
    • http://sintellect.ru/Repository/file/51183373250.pdf
    • http://aytekinpolatel.com/image/files/basatarejalabuvebawobe.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/5a6010af9cd0e005ce905117d769aef1/zijavopetinovowomozenot.pdf
    • http://ajivikafinance.com/userfiles/file/nufovujajivufeberubixatud.pdf
    • http://www.ks-zahnarztpraxis.de/upload/files/48499513000.pdf
    • http://www.heksan.com.pl/file/xizepalugedotova.pdf
    • http://monkey-do.net/userfiles/file/62205095340.pdf
    • http://aerotechgroup.ru/img/outer/files/19898518393.pdf
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cfb0d9a5fef---80412373045.pdf
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/a8a313bad42027cd12f6f955aed93d48/70917617486.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/b4276213ce7370c03f14440a34dfdfea/9004875830.pdf
    • http://bigbazar.cz/is/images/FCKeditor/File/rerifimafozif.pdf
    • http://tieclangman.com/Images_upload/files/4243980256.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=prentice+hall+mathematics+algebra+2+answers+pdf
    • 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_off0000c556.bin
2d0f40384980c0ff3b4eca6ca62f3ef871c45a30de332ab4b687f72658e1dfdb
pdf-font-stream PDF embedded font (sfnt) at offset 0xC556 11292 bytes
font_01_sfnt_off0000df58.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF58 16792 bytes
font_02_sfnt_off0000f76a.bin
bbe9b0a335ea543e001677e9cb6c008ba20cda6348d1e284f2bb7c585ee9cfc0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF76A 15680 bytes