Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c4d19b38b5e120b…

MALICIOUS

PDF

80.4 KB Created: 2021-09-17 14:30:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: feaf367255c7729535b262e9b4399483 SHA-1: 1fd911688825952a91003e6148c9dbbdd9d39b5d SHA-256: 8c4d19b38b5e120bf1250b014099e612bbd2f6c7263724bd2c39d78f2d6b9bcf
96 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs, many hosted on compromised WordPress sites or disposable domains, indicating a potential distribution point for malicious content or phishing. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple external URIs supports a malicious intent. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://prompol.com/media/file/kudosotugobuxutagotejumak.pdf In PDF document text
    • https://novinfasteners.com/userfiles/file/26121097574.pdfIn PDF document text
    • http://guitarenko.fr/img/files/vifobajezatojima.pdfIn PDF document text
    • http://blfimmobiliare.com/userfiles/files/guline.pdfIn PDF document text
    • https://asfus.net/virgsurv/userfiles/file/luzagimuwiniru.pdfIn PDF document text
    • https://sibois.eu/userfiles/file/70093632899.pdfIn PDF document text
    • http://extrastyle.ee/ckfinder/userfiles/files/6188580956.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/161390a1a5339a---21949153829.pdfIn PDF document text
    • http://cochemical.com/upload/files/jubosobirivobu.pdfIn PDF document text
    • http://hkacca.com/userfiles/64191342140.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16142b5606d6c1---11751932782.pdfIn PDF document text
    • https://iaido-iaijutsu.ru/userfiles_exc/75427059791.pdfIn PDF document text
    • http://sun-tes.ru/files/file/mobidunetamipotekep.pdfIn PDF document text
    • https://www.highettmetal.com.au/application/third_party/ckfinder/userfiles/files/32717579524.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/16137b554c90bc---nolapevarap.pdfIn PDF document text
    • https://ssmahavidyalaya.org/lion/uploadedfiles/fck/files/file/fifojixatuw.pdfIn PDF document text
    • https://drnanemilk.com/tctt/sites/aaa/file/nawoviwesok.pdfIn PDF document text
    • http://woodbridgeabw.com/uploads/files/60306071765.pdfIn PDF document text
    • http://h04ydivan.ru/userfiles/file/bajawi.pdfIn PDF document text
    • http://dieukhactransam.com/uploads/files/wutuvumajuzu.pdfIn PDF document text
    • http://kingkady.cn/uploadfile/files/44963965944.pdfIn PDF document text
    • http://lsneotek.com/ckupload/files/81171054777.pdfIn PDF document text
    • http://asid.rw/userfiles/file/giseniwubebukipugudamek.pdfIn PDF document text
    • http://ipceurope.com/assets/file/93161442999.pdfIn PDF document text
    • http://evrokomplekt.ru/userfiles/file/repuw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=text+twist+2+apkPDF 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_off0000d57d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD57D 10236 bytes
SHA-256: 0630dd76c4b39df76aa3b5272a31d597f1e6856c4a77fdb4773d5fd95b2a78bc
font_01_sfnt_off0000eccf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECCF 18288 bytes
SHA-256: 939430e724ad0ca41766243a9fcc9db31b19d054662d40e925afc480a27d4e6f
font_02_sfnt_off00011c63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1