Malicious PDF — malware analysis report

Static analysis result for SHA-256 f31e101e6181f0eb…

MALICIOUS

PDF

84.2 KB Created: 2021-07-20 03:14:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 55f5807996973445abf80107d7077b6f SHA-1: 283ee4ed3bde7e8e8845bcbc90955817d029f5c4 SHA-256: f31e101e6181f0eb04ee18495ca026bc1cd55321e75422f10cc2d1c75a81541d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The document contains a large number of external links, many pointing to compromised WordPress sites and disposable domains, suggesting it functions as a link farm to distribute further malicious content or phish users. No scripts were extracted, but the nature of the URLs and the detection suggests it's designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • 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.
  • 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://4bx.pl/public/file/76591047339.pdf
    • https://shayangroup.net/wp-content/plugins/super-forms/uploads/php/files/8e8497bbecead88531de5f83168e619b/94000987938.pdf
    • https://art-eria.pl/mandarynka/pliki/files/21557985379.pdf
    • http://inezorviskids.com/clients/37546/File/zixunowiwokemuwogekip.pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608b7a3e72b1a---sajoropurag.pdf
    • https://cedarcreeksauce.com/wp-content/plugins/super-forms/uploads/php/files/b0eb40b6ac43f075dd1b83739a15be3d/tavijopujamevilasisodarek.pdf
    • http://barcelonasixtytwo.com/userfiles/file/zuziru.pdf
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160c08ad1cfc7f---muwomipi.pdf
    • http://mikailang.net/userfiles/file/20210509100447_1288962421.pdf
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/366uqbn3a5b1cus1jnm97h6g65/23338914618.pdf
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/24721f1f4409e1d59b65f6fb3db208a6/87908099446.pdf
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/68f54bddbf74d90ddbbf7a22e1bbdc20/majofigivaduveroregoluna.pdf
    • http://niszczeniewaw.pl/userfiles/file/fopiwadirixaweboxuzubiri.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160cecf2ce40d6---84930330504.pdf
    • http://pvhs1967.com/clients/a/aa/aa78cb05297cd93d8a9ab6bd1eb8a3c4/File/koganaguwaruzolajasaf.pdf
    • https://www.winsum.frl/ckfinder/userfiles/files/34182619631.pdf
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160f1713069040---fubobus.pdf
    • https://everestart.com/images/stories/file/nubudojulekaseg.pdf
    • https://holocaustresearch.pl/nowy/photo/file/16841559467.pdf
    • https://chp-travel.ir/data/file/sesilinud.pdf
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/nr2r4afjvrkikcvlplrs458d82/zomuwazamolavojorevosaf.pdf
    • http://huijingweb.com/upload_fck/file/2021-7-17/20210717204250532731.pdf
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/47l4bmdl06hqbi3ihqkbsnd4hq/12988946530.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=whole+grain+mustard+balsamic+dressing
    • 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_off0000e5c1.bin
a9023590093a3c05bab8ed52326e15013c7cce5470b2d1c1d12b77436b4d3de7
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C1 11048 bytes
font_01_sfnt_off0000ff1a.bin
9f5bbfb95f3d8fa9472c17509f58a579b432081b5b253843b39796520a7d82cb
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF1A 16932 bytes
font_02_sfnt_off00012b76.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B76 16792 bytes