Malicious PDF — malware analysis report

Static analysis result for SHA-256 726bfe84680b56a9…

MALICIOUS

PDF

75.3 KB Created: 2021-07-01 10:49:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 10877b1eb7a11ac1c6746b95c47958a8 SHA-1: 2578b286a147f7e4c39062a626e872b215c3bf66 SHA-256: 726bfe84680b56a93530b916339e47b87ead3fc334620edb67b91f8edb4a6349
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised WordPress sites, indicating a link farm or SEO poisoning attack. The ML classifier strongly flagged this PDF as malicious. The presence of external URIs and compromised CMS upload links suggests the document is designed to redirect users to potentially harmful content or facilitate further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 5

  • 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://inwebjor.ru/uplcv?utm_term=the+domain+of+square+root+functions
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/4985cee7bd80ef3288f37a83e484b4db/5499522809.pdf
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bc6309e0384---muzokajexidel.pdf
    • http://rudolphalexander.com/uploads/files/48393821595.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/af19495bc74d28fa17aeb966b5430cf0/suxawabojetulilovuxe.pdf
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/e598780bf2dc08be3439cf46d9f16385/megizubozasireniza.pdf
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/83je7ba4rrc4vr3sqknsg7vvgu/2277878353.pdf
    • https://landatur.com/files/galeria/files/zafobavedolamuxabip.pdf
    • http://thamdinhgiadaiquang.com/img/files/balalawesilaxilumo.pdf
    • http://hzkontejnery.cz/ckfinder/userfiles/files/bevugolixajorisobunuxorux.pdf
    • http://dragonera.cn/admin/userfiles/file/42261398225.pdf
    • http://dush-kz.ru/uploads/fck/file/2094788575.pdf
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608abf3045a1f---88559437779.pdf
    • http://baovephuongtroi.com/vietkiendo/upload/file/dudabuberibes.pdf
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/9608ebc4c4382ee04c536a4e79fffa14/rarojuvolokunepazenirekix.pdf
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160ce965bb8a0c---rajamivulekabivo.pdf
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/dedf1cb525e12a32703c84757a1ef6e2/buwibifuja.pdf
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608624d46fc99---vugefaneg.pdf
    • https://cpsguffanti.com/uploads/file/pakoxibapesekifuvu.pdf
    • http://snsi.jp/image/news_file/jovopep.pdf
    • http://tachikawa-derma.biz/ckfinder/userfiles/files/sezulojonimubafokid.pdf
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c1e99998ad---53780527570.pdf
    • https://deltagroup.bg/uploads/file/mizepurebesojemef.pdf
    • http://saiprogetti.net/userfiles/files/kuraka.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e52e637cc7---rukuzibewoje.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_off0000c389.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC389 16792 bytes
font_01_sfnt_off0000dba0.bin
49073e2b7971faaa0f2729b2f1637798077d9e80b32b7b47ceef2531034ea278
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBA0 10904 bytes
font_02_sfnt_off0000f47e.bin
8528fd89363fd4681592d86ed89be8b7564445f72227c891c08e6e77352b3236
pdf-font-stream PDF embedded font (sfnt) at offset 0xF47E 16632 bytes