Malicious PDF — malware analysis report

Static analysis result for SHA-256 3442a620faef6e94…

MALICIOUS

PDF

82.4 KB Created: 2021-09-14 10:28:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 64e5db081832826bd377f2bd0f31f4b9 SHA-1: f395a901bd50fd9c51e27fccf617200e18abaeb1 SHA-256: 3442a620faef6e944ab7e34689844a6349598f9c0b3028668cfa9ef053bfe951
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous external URLs, many of which are hosted on domains flagged as potentially compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine its function as a malicious link aggregator.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 https://karapinler.com/calisma2/files/uploads/nofojaxitox.pdf
    • https://inoxquochoang.com/app/webroot/files/images/pages/files/92114258608.pdf
    • https://cmoretv.com/userfiles/jarikekuwof.pdf
    • http://bienbao.net/uploads/files/41860522253.pdf
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/91e27548457e46ee099d57b151eed4c9/61445567555.pdf
    • https://mobilpetrol.olajpark.hu/files/files/34861666630.pdf
    • http://newshop.jp/archive/file/93887748883.pdf
    • http://www.louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/5328566043.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/h7erghssafudbhq7lik1q4vjr2/34107895277.pdf
    • http://kaushalacademy.org/ckfinder/userfiles/files/15790494799.pdf
    • http://farmandari-sarvestan.ir/images/news/files/26962379693.pdf
    • http://swotaweb.com/img/upload/file/janikonurewuteni.pdf
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/ccb873454419a04ff3e91966267a3c2d/tafitixemukozinozub.pdf
    • http://deleeuwputten.nl/site/data/ws/files/1874854297.pdf
    • http://brixtontaxi.com/survey/userfiles/files/sirijop.pdf
    • http://floridadressyourhome.com/uploaded_files/userfiles/files/sarerabimuf.pdf
    • http://infrabud.eu/fckpliki/file/70088292743.pdf
    • http://artsar.pl/userfiles/file/6655530900.pdf
    • http://yuh-tarng.com/userfiles/file/27310325819.pdf
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/36a6fa4a8180e2bbbab028e6e134e4df/28029814503.pdf
    • https://mgrenginiai.lt/ckfinder/userfiles/files/70265849614.pdf
    • https://kalyna.ua/sites/default/files/userfiles/file/97093551879.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/db4e0849fdb4588cbfca1f83f5e6e256/41143121026.pdf
    • http://bagodilovaspark.hu/userfiles/file/sugoluduzig.pdf
    • http://japanbizkorea.com/userData/ebizro_board/file/91166648573.pdf
    • http://satunatc.ac.th/ckfinder/userfiles/files/nitujetala.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=what+to+say+when+emailing+your+cv
    • 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_off0000db27.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB27 16792 bytes
font_01_sfnt_off0000f33e.bin
31726e5defb7e8b8d224bb8529b8d1c674c7fec620660d2a22707cbf760bdd7e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF33E 11036 bytes
font_02_sfnt_off00010cd1.bin
c35163185b47cf4ad2564619313d30faf5b666769f7967c2a0dc1d0fe1fd1760
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CD1 17992 bytes