Malicious PDF — malware analysis report

Static analysis result for SHA-256 a553d4754d0a8330…

MALICIOUS

PDF

72.4 KB Created: 2021-09-21 04:03:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9dfcab73eb449717fcd1025609cc62b8 SHA-1: 42bfc3c19f62c0a1a6dc0e34f66087d1155df569 SHA-256: a553d4754d0a8330c129e98458d11ec9ad117a764d1a8f17399aa2ccd7fe7f35
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised websites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, with the primary goal being to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://jogamiskolc.hu/ckfinder/userfiles/files/wufomalirogonu.pdf
    • https://nacionalequipamentos.com/ckeditor/uploads/files/rurokowilurasusefod.pdf
    • https://huaku3c.tw/uploads/files/202108312151341507.pdf
    • http://thesprotia.gr/uploads/file/gewajebufelugak.pdf
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/04aef62c9b67c4740c476eab2c62e64d/fixisifajozemitiba.pdf
    • http://perilatomsk.ru/ckfinder/userfiles/files/somepifef.pdf
    • http://namadagaskare.ru/ckfinder/userfiles/files/paputusu.pdf
    • https://tradingphrases.net/userfiles/files/xarixalo.pdf
    • https://interstudy.net/userfiles/file/13585388883.pdf
    • http://cassotech.nl/site/data/ws/files/27091565187.pdf
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/rekurivifasa.pdf
    • https://pametnidom.hr/pametne_kuce/userfiles/file/32124416428.pdf
    • http://addon-colsman.somantec.net/ckfinder/userfiles/files/pojokowokaribak.pdf
    • http://czechdidgeridoo.com/admin/upload/file/29480967824.pdf
    • http://bacvietexpress.com/upload/userfiles/files/44269055205.pdf
    • http://nakamurasangyou.jp/app/webroot/uploads/files/mudutanirutizewobi.pdf
    • http://yaqeen-eg.com/userfiles/file/23610032591.pdf
    • https://5of7edwardstreet.com/assets/media/files/dapipifiluperolewijevo.pdf
    • http://wignaccent.com/FCKeditor_2.6.3/userimages/file/20210917233133.pdf
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16140e8037d043---sasozusuzutopavadetawo.pdf
    • http://marktoby.com/akram/know_news/admin/userfiles/file/wafojogefuxawos.pdf
    • http://vucert.vn/uploads/files/31871974731.pdf
    • http://printific.com/images/contentimages/files/36434014480.pdf
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/pvhqhdskjvu8vjbhf72ge60qqm/juwadorotisa.pdf
    • https://cualuoihoanmy.com/uploads/userfiles/file/55544064252.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=ace2three+plus+app+apk+download
    • 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_off0000b856.bin
91c3389c320b009e3bd2e09d65c568966735c7261e62d86a16a33c9b5a3d3226
pdf-font-stream PDF embedded font (sfnt) at offset 0xB856 16472 bytes
font_01_sfnt_off0000e256.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE256 16792 bytes
font_02_sfnt_off0000fa6d.bin
2244060152a4d4ea140ae900a9f8acf3cbf7cda4a2a9dd9948c6dc2a99a5a72a
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6D 10896 bytes