Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff0c9273da236b76…

MALICIOUS

PDF

80.5 KB Created: 2021-09-13 23:28:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 82a50a2f241786e1edac04d89479ce11 SHA-1: 527b5037f4f3862c62994c68591c114d0e42c94e SHA-256: ff0c9273da236b76723633a50936551dd888623d215c2043e9f423ee88546ae8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a large number of external links, many pointing to compromised websites or disposable hosting. These links form a link farm, likely intended to redirect users to phishing or malicious sites. The ClamAV detection and ML classifier strongly indicate malicious intent, consistent with a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • 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://krisoc.ru/uplcv?utm_term=how+get+cod+points
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/xaroka.pdf
    • https://oilbasaro.com/web/images/ckfinder/files/20210902210850.pdf
    • https://longislandinvestmentadvisors.com/nini/userfiles/file/36722637730.pdf
    • https://everestart.com/images/stories/file/31918027074.pdf
    • http://hpworld.hu/data/pic/Image/file/2217221142.pdf
    • https://ud-hobby.com/images/Upload/file/93378498189.pdf
    • https://thefertilizerproductionline.com/d/files/48177273392.pdf
    • http://rapet.hu/files/leburizufevog.pdf
    • https://inijariku.com/ckfinder/userfiles/files/26269143250.pdf
    • http://baschin-heizung.com/meineBilderAlbertGrundschule/file/dikexofopilewalev.pdf
    • http://dansungsala.com/uploads/files/19298717338.pdf
    • http://tranindo.com/Uploads/userfiles/files/64179530988.pdf
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/5708fbb3c24f3770ef9e51d2f49ad1a3/36103033130.pdf
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16136fe33c2362---81929050551.pdf
    • https://yomadesign.com/userfiles/Proj_Name/files/23775739003.pdf
    • https://vadihosting.com/calisma2/files/uploads/30624934299.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/2b67a0ae7acb89eb9e375edec2b433c7/50965292664.pdf
    • http://gold-carsales.com/js/upload/files/33008799097.pdf
    • https://almondzwealth.com/administrator/imagetemp/file/54605071894.pdf
    • https://wroclawmodelshow.pl/ckfinder/userfiles/files/27746515331.pdf
    • http://mtsp.by/userfiles/files/kudatitonaworeno.pdf
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16131ba10ad686---golokafebatajofow.pdf
    • http://unipsyclinic.com/userfiles/file/20210906030053.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_off0000d364.bin
5e94e0bd2d86568fad717bca09fdc7ca0b9e299f4fb8b185eed46c1c1179ddea
pdf-font-stream PDF embedded font (sfnt) at offset 0xD364 19124 bytes
font_01_sfnt_off00010487.bin
0212b89eca6ca5676176e6e342ffbda68053bde35882d101a569bb03fa51c4da
pdf-font-stream PDF embedded font (sfnt) at offset 0x10487 10460 bytes
font_02_sfnt_off00011c36.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C36 16792 bytes