Malicious PDF — malware analysis report

Static analysis result for SHA-256 257953c3ab7de518…

MALICIOUS

PDF

84.2 KB Created: 2021-07-10 08:02:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a0338f9ed79f327bf05ec9aea7d465e1 SHA-1: e15708a50c6175987e66c3dab2344761122cf25b SHA-256: 257953c3ab7de518bea978e581a545b07ea3947869652ad8c72ee18c679931fe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and link farms, many hosted on compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were directly extracted, the structure and URL patterns are consistent with malicious PDFs designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://krisoc.ru/uplcv?utm_term=app+to+facetime+android
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bd636ef2d25---dikewoliwigibapofokowisa.pdf
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084e25ed953c---32442077269.pdf
    • http://volamtuyetthe.com/userfiles/file/danamu.pdf
    • https://biogenetixpharma.com/ci/userfiles/files/95649621948.pdf
    • http://yummyschool.com/_UploadFile/Images/file/zigepijajetanavivexizow.pdf
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/d2cf47f00dcfea3db91a13b166b2064e/1544653666.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081dad48a406---figururanatem.pdf
    • http://ahkjt.com/upfile/file/62280325540.pdf
    • http://botosani.ro/img/uploads/file/95868916652.pdf
    • https://amatnieks.com/pictures/image/35173759409.pdf
    • https://investmentskillsgroup.com/images/userfiles/file/valuxunegeritemomede.pdf
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7e429dff3---jodakekixof.pdf
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e28f29aa77---sexaruxujaxadapitamezosaj.pdf
    • https://bevillelecomte.ovh/ckfinder/userfiles/files/57972853733.pdf
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607e58c1a87e9---lovinogojelameligazinipi.pdf
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/7vl4eu48rvohmk7spf02deotfn/67767969234.pdf
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16084e5dd208df---86341615303.pdf
    • https://fallahi-sch.com/userfiles/file/zameje.pdf
    • http://didula.com/img/file/54573001994.pdf
    • http://myshopekerala.com/userfiles/file/99481221496.pdf
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/16090f166280ae---xodomisoji.pdf
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b4c35782065---92537311266.pdf
    • http://colegiosantarosa.com/uploads/imagem/file/55413970023.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_off0000e7f5.bin
b9933f4b830aecc4db5d94494538f2809ec8840ef4bc1c8ef3759dada5b53435
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F5 10548 bytes
font_01_sfnt_off0000fff8.bin
94e2d2e6889d562e843695a11cb80c8ae5611cc2419c7296751e3c154f49946a
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF8 16812 bytes
font_02_sfnt_off00012bcb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BCB 16792 bytes