Malicious PDF — malware analysis report

Static analysis result for SHA-256 33a79cac8529885e…

MALICIOUS

PDF

77.8 KB Created: 2021-09-10 11:57:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1fef53b3dc5ba35f6cde7a28e6bf0694 SHA-1: 35291619e49a39a1ec8e0e1dfb39d92a30fdbc1d SHA-256: 33a79cac8529885ecd937ad6b8567ca52b9c3868747ad4c8c432c883cd3de72b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external links, many of which point to compromised websites or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the presence of URLs like 'https://inwebjor.ru/uplcv?utm_term=download+miui+12+for+redmi+8a' suggest a phishing or malware distribution attempt. The embedded JavaScript likely facilitates the download and execution of a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://inwebjor.ru/uplcv?utm_term=download+miui+12+for+redmi+8a
    • http://dekogard.net/deko/veri/_files/degubawuviwepubumibi.pdf
    • http://tamtamphat.com/upload/files/jikibakidaxazadi.pdf
    • http://www.physedu.in/newsite/userfiles/files/15940245870.pdf
    • http://rotarycochinharbour.org/ci/userfiles/files/49442636748.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/udcos8ckjdgpj90p4ouhotmvoc/safunotagosenejodalaret.pdf
    • http://teplospectr.ru/images/files/34325805746.pdf
    • http://due.pt/js/ckfinder/userfiles/files/77553960911.pdf
    • http://progfin.pl/userfiles/file/puzaduzubavopafulasomofoz.pdf
    • http://ville-dammarie.com/ckfinder/userfiles/files/44552583648.pdf
    • https://juhaszautovill.hu/userfiles/file/pakugazakusakevuxufe.pdf
    • http://bbu.vn/Images_upload/files/53039253903.pdf
    • http://gat-asset.com/CKEdit/upload/files/91276808205.pdf
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/0ffbf1b884659f66491126a050101698/redizufawedejukatawuwubel.pdf
    • http://belly.bpv.su/content/files/files/50875695943.pdf
    • http://wxmx.cn/upload/ckimg/files/202109081119185214.pdf
    • http://njbeihang.com/uploadfile/file///2021090415544724.pdf
    • https://tavcam.com/upload/ckfinder/files/vaberusiwerejuvedoredemuv.pdf
    • http://rockhouseschool.com/rockhouse/uploads/files/suxapavigarevomavej.pdf
    • http://tvsatkrosno.pl/userfiles/file/44608970932.pdf
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/161356ade1d1fd---79556781268.pdf
    • http://www.bsa.by/ckfinder/userfiles/files/57752215859.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/161363e09ea787---25266165482.pdf
    • https://willes-gb.com/uploads/files/202109080049326949.pdf
    • http://kyea.org/imageuploads/sugelepiwukizalofu.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_off0000c3be.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC3BE 16792 bytes
font_01_sfnt_off0000dbd0.bin
7b9b7c2470d0481cf12d9ce6fe54e18bf791d795ba905de02324d029bbc49697
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBD0 20652 bytes
font_02_sfnt_off00011064.bin
c8d13f08baa5d9ceafb376e9c00ab24c2361f6974fe65dc01aeb894ae9935feb
pdf-font-stream PDF embedded font (sfnt) at offset 0x11064 10816 bytes