Malicious PDF — malware analysis report

Static analysis result for SHA-256 48a97f44f950ea8d…

MALICIOUS

PDF

79.1 KB Created: 2021-09-06 04:50:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c5533eb4630f607b808f6f32077d2cba SHA-1: 6d039592bf6cc6c24c5777ca58f5b637d2b0176a SHA-256: 48a97f44f950ea8df080a4f7282cd28cd250270f0d45db3ac5065afbbf2c423d
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to disposable hosting or compromised CMS upload directories. The ML classifier strongly indicates maliciousness, and the link farm structure suggests an attempt to manipulate search engine rankings or distribute malicious payloads. No scripts were extracted, but the overall pattern is consistent with a malicious document designed for initial access.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://sky1981.com/asset/uploads/files/17026648909.pdf In PDF document text
    • http://titadoorbinhduong.com/upload/files/lavexaku.pdfIn PDF document text
    • http://shinex-auto.com/userfiles/file/11360414798.pdfIn PDF document text
    • http://klasykarozrywki.pl/public/images/fck/file/60569502052.pdfIn PDF document text
    • https://mabuksusu.com/contents/files/63284193078.pdfIn PDF document text
    • http://cosmoscm.com/contents//files/zukigomuzudigilaxotixoge.pdfIn PDF document text
    • http://jainfarms.com/uploads/niweda.pdfIn PDF document text
    • http://alda.pl/ckfinder/userfiles/files/42227678103.pdfIn PDF document text
    • http://vce34.ru/attachments/file/32534111378.pdfIn PDF document text
    • http://timebymtm.com/upload/files/18713688829.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/55caljm3c3k3m01jkq9hjvt8od/30028390053.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160cf5f5a3f066---7488989983.pdfIn PDF document text
    • http://extintoresorigen.com/images/editor/57054086681.pdfIn PDF document text
    • https://maxlinder.com/admin/assets/ckfinder/userfiles/files/26899427717.pdfIn PDF document text
    • http://babyschultz.com/clients/72285/File/13140739528.pdfIn PDF document text
    • http://cdmatik.com/uploads/file/pivarugebosejalizopar.pdfIn PDF document text
    • https://angkortaxiservice.com/userfiles/file/xuvubutagofujavoruwifemed.pdfIn PDF document text
    • http://reklama-kemerovo.ru/files/files/13442383817.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16082e3aa28b6e---31388765117.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612025623842f---xasedotef.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/07bd0d55c80acf035ef99646c1631d08/46240312293.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/01k6ifu2jgen0vsbtumic0okqr/munonigawufu.pdfIn PDF document text
    • https://monyetmesum.com/contents/files/wuwufejusitovedabikimepo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=alphabet+letters+worksheet+freePDF 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_off0000d127.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD127 17628 bytes
SHA-256: b1840e7e31d4e915dcfde0864e4668f7ce4edb895b8aa56d2c2afd093ff2aeca
font_01_sfnt_off0000fe50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011667.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11667 10560 bytes
SHA-256: 83f40e4636c5d18f735a427efc1b42f210c4abcdc9af94ce29ace9297aa049f8