Malicious PDF — malware analysis report

Static analysis result for SHA-256 39991171cec91f01…

MALICIOUS

PDF

85.9 KB Created: 2021-09-17 01:34:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8bef03755526003a8e3be86ea905c4e5 SHA-1: d779d2020e912cca4c748b495db8acbb9bcd2303 SHA-256: 39991171cec91f0101e2a600a12137b540be22ea88e24ba07e6d4398ee5d8d7b
124 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external links, many pointing to compromised websites or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicate a pattern of using link farms for SEO manipulation or to host malicious content. The embedded JavaScript suggests potential for further malicious actions, such as downloading additional payloads or redirecting the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://infrive.ru/uplcv?utm_term=acrobat+embed+fonts
    • http://celeb.huh.hu/UserFiles/File/datodagivedojof.pdf
    • http://www.mmd.ntou.edu.tw/ckfinder/userfiles/files/85454315546.pdf
    • http://elrey-uslugi.ru/media/file/gomimibesesuvalulikeduke.pdf
    • http://delfosventures.com/userfiles/files/33976808006.pdf
    • http://taxicityplus.ru/userfiles/file/dogola.pdf
    • https://bem-sa.com/img/file/19229796916.pdf
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/161422555302ea---wasulinimodimagosatunega.pdf
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e7f2f7ba02---33499728007.pdf
    • http://phongthuyphatloc.com/luutru/files/lebizadepigedogosatupa.pdf
    • http://monthclean.com/uploads/files/202109161718483135.pdf
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16143b63d0e855---75748896733.pdf
    • http://www.cerathai.com/image/upload/File/xewojoku.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134e7e174543---bodikovaja.pdf
    • http://www.letnifestiwal.pl/ckfinder/userfiles/files/34169223284.pdf
    • http://iraneto.com/basefile/iranetocom/files/niwekuzoj.pdf
    • https://shoppingplanet.ro/ckfinder/userfiles/files/xigosulutatu.pdf
    • http://studiogiamberardino.it/userfiles/files/dalelim.pdf
    • http://mrhobbscoffee.com/images/uploads/file/19344336044.pdf
    • http://loscogliodifavignana.it/userfiles/files/12010472776.pdf
    • http://sincaremedicaltour.com/js/upload/60679114475.pdf
    • https://art-gallery.mn/uploads/files/ximukakudexadoxutom.pdf
    • https://inprovitvenezuela.com/ckfinder/userfiles/files/41557388625.pdf
    • http://radio-salsa.fr/php/rs/filesupload/file/rudijejejunasenuzezojifeb.pdf
    • http://studiotipaldo.com/userfiles/files/60922811791.pdf
    • http://hansungid.com/userfiles/file/dovodolaletefomajob.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_off0000e7f4.bin
5362533339699dcab55d898702e1de7b726327f00765d439c9fc26a59f875336
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F4 19268 bytes
font_01_sfnt_off00011983.bin
d548e550f8d6c363b74fcda89d5b70b99f772394f6331909916d048e8e29730f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11983 10620 bytes
font_02_sfnt_off000131d9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x131D9 16792 bytes