Malicious PDF — malware analysis report

Static analysis result for SHA-256 e58f5cf0e911c46f…

MALICIOUS

PDF

71.8 KB Created: 2021-09-09 15:03:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 5dae89c8040750f54208d2d7fae7c2b7 SHA-1: ecbee5a037f893f60d850022c7179e2110ce9c85 SHA-256: e58f5cf0e911c46f86f054cb52145571dcb39ccd84f1a2c5df717e3ab8da64ca
156 Risk Score

Malware Insights

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

The file was identified as malicious by ML classifiers and ClamAV, flagging it as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to other PDF files hosted on various domains, some of which are associated with compromised CMS uploads. The document body is heavily obfuscated, preventing a clear understanding of its direct intent beyond serving as a redirector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://imosa.asia/uploads/files/202109081501581449.pdf In PDF document text
    • http://sprinter-lab.ru/content/File/51496302353.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/12812210993.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138fc282d445---diferemexozames.pdfIn PDF document text
    • https://lawina-radom.pl/files/file/susofasevufu.pdfIn PDF document text
    • http://eltdb.com/UserFiles/files/rodaf.pdfIn PDF document text
    • http://bowie.abwingsmd.com/uploads/files/silobero.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/doxeti.pdfIn PDF document text
    • http://samafb.org/uploadfilefiles/gepigorira.pdfIn PDF document text
    • http://www.somdattabasu.com/fckimages/file/55815291561.pdfIn PDF document text
    • https://pasifikendustriyel.com/userfiles/file/48469128406.pdfIn PDF document text
    • http://gerastar.com/userfiles/file/50509174966.pdfIn PDF document text
    • https://landtop.com/filespath/files/20210909115453.pdfIn PDF document text
    • http://kimyasaldubeller.com/upload/ckfinder/files/93149676777.pdfIn PDF document text
    • https://ncltandatbar.com/home/ncltandat/public_html/dowalumniusa/ckfinder/userfiles/files/30671661297.pdfIn PDF document text
    • http://nova-auto.com/upload/2851297522.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/dutixufagaponexuvulod.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/161361f6a82083---7927709513.pdfIn PDF document text
    • https://academiapreprod.riportico.com/userfiles/files/47882589453.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/1cb94d2d57117f603da24001fa2421ab/xitefib.pdfIn PDF document text
    • https://binarbaidfabrication.com/public_html/userfiles/file/96043393784.pdfIn PDF document text
    • http://jts-electrical.co.uk/ckfinder/userfiles/files/katelas.pdfIn PDF document text
    • https://franchise-vietnam.com/app/webroot/img/files/14471374736.pdfIn PDF document text
    • https://cdmsig2.com/ckfinder/userfiles/files/25602861770.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=discrete+mathematics+with+applications+susanna+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b2da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2DA 17744 bytes
SHA-256: 4189c344fdb805090d5ea2759da6c79a395f95165cbf64b7b534e57432e1016c
font_01_sfnt_off0000dfb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f7ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7CE 11072 bytes
SHA-256: cb04a54cd7f673e9a29868c742a190cdd23345c1f862e2f333b9d0aaf9815e0c