Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91f0c736f08e4d2…

MALICIOUS

PDF

77.3 KB Created: 2021-09-19 13:50:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 87dce5fee1f7db74a33a3e97caac35e1 SHA-1: 4a3cbd2f7378a965109564c976c8a4e3f628f26a SHA-256: c91f0c736f08e4d2a94b97a052e0c18596c53e4b82556e2b5de517dedb719a67
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The presence of a ClamAV detection for 'Pdf.Phishing.Trojan' and ML classification further supports its malicious nature. The embedded URLs, such as 'https://archism.ru/uplcv?utm_term=run+apk+on+windows+10', suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://archism.ru/uplcv?utm_term=run+apk+on+windows+10
    • http://daglichtfilters.nl/ckfinder/userfiles/files/67195312161.pdf
    • https://viscom.bg/uploads/wysiwyg/files/88069727101.pdf
    • http://nesthomes.in/userfiles/file/7755694033.pdf
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/s23rt34e2b371879fl3114j8t1/zulosanupimanaladokovanib.pdf
    • http://dui-antidote.net/images/userfiles/file/94477978514.pdf
    • http://kledingindex.nl/images/uploads/64156152319.pdf
    • http://nousgarage.com/userfiles/file/femabuxef.pdf
    • http://platypusspot.org/uploads/ckfinder/userfiles/files/liropudamufajuja.pdf
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/894104256134550f64e90.pdf
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613a772fe1c14---56411326254.pdf
    • http://dlastudenta.org/Upload/file/kunobenujoji.pdf
    • https://rougezenekar.hu/files/file/12232758992.pdf
    • https://mosallaesf.ir/uploads/ck/files/fanusizuwomupu.pdf
    • http://napiarsaigh.com/images/suwizab.pdf
    • https://camgloberealtor.com/userfiles/file/lipudivipupasures.pdf
    • https://sukienmiennam.com/userupload/files/71931056069.pdf
    • https://estatecambodia.com/htdocs/cljr/data/files/fodujezu.pdf
    • https://kolbandibileklik.com/resimler/files/vedamogejiwefogoregolo.pdf
    • http://gfb.it/upload/fck/file/37569314960.pdf
    • http://mq-water.net/upload/97367598680.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138fb5184b97---3352657991.pdf
    • https://inprovitchile.com/ckfinder/userfiles/files/joxuxovuzogop.pdf
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614638d71e841---93823797583.pdf
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/hu1o74vhf181uh41adi40rm421/47398100739.pdf
    • http://ruizhishengwu.com/uploadfiles/file/132114074569.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_off0000c9d5.bin
803cbe826f5903a1c8fe9cbf99499df160681f7d46056a774b25550e3f5b028e
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9D5 17800 bytes
font_01_sfnt_off0000f7b1.bin
081bc46a65aea05568a8ab07043e80be65bc0ec87bf124ba7fa6ef039917e163
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B1 10504 bytes
font_02_sfnt_off00010fcc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FCC 16792 bytes