Malicious PDF — malware analysis report

Static analysis result for SHA-256 951a96023e3c72ad…

MALICIOUS

PDF

80.1 KB Created: 2021-09-19 19:48:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2137cb91abdbdec0239eab284f9f6a53 SHA-1: e0930419727c81895414f6e75092faed6a4c5420 SHA-256: 951a96023e3c72ad956574c9ef15dff86c77487c17db14d201b677dcd37b8331
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many of which point to compromised WordPress upload directories, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or delivering a secondary payload. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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.
  • 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://optimuselearningschool.aels.edu/learning/site/images/uploadfiles/21733533575.pdf
    • http://kazuma.ru/ckfinder/userfiles/files/99831433213.pdf
    • https://satnamunicipalcorporation.com/admin/ckfinder/userfiles/files/perimozitixib.pdf
    • https://simpangkanan.com/contents/files/10042492977.pdf
    • http://fmafirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xixeraliwululiguriken.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143940eab3d5---93877092089.pdf
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/ovha87chddkll9k39dvigsf0h1/xivurizuxutusavatoxefefa.pdf
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/borawonoxovolesolit.pdf
    • http://rnralpha.cz/res/file/kebitoda.pdf
    • https://mmtours.si/uploads/gitefedixer.pdf
    • http://ckudzcssffhhj.handysociality.com/upload/files/kufokosezelor.pdf
    • http://redeyeldn.com/userfiles/file/latuxo.pdf
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/kdv2c1kincpvjnn947p7h7lm46/89287483814.pdf
    • http://sb-78.ru/files/file/jeleripevowunutesasovofux.pdf
    • http://csc-0898.com/userfiles/file/20210902042022_dbtccf.pdf
    • http://ruizhishengwu.com/uploadfiles/file/061259541546.pdf
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16146a0220a1b6---ririza.pdf
    • https://www.agencesramos.com/ckfinder/userfiles/files/jafan.pdf
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/1159834516.pdf
    • http://usagimatur.com/files/others/59286438296.pdf
    • http://accapierre.it/userfiles/files/sujorivizojekuwa.pdf
    • http://moristas.com/userfiles/files/26606028182.pdf
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/161360d3418155---janopa.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16130653f4d3a0---rajimosigulapafivusiv.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=he+set+the+captives+free+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_off0000d696.bin
11c7a9c9cdcadccd5d07de8b41100bba9656ac56ad3393d21a1dc98f740aa14e
pdf-font-stream PDF embedded font (sfnt) at offset 0xD696 17388 bytes
font_01_sfnt_off00010319.bin
54b9b4b6ef19e75ab45a35b0eec87d17c9d783f80b6334974157e817bb856ec1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10319 10504 bytes
font_02_sfnt_off00011b22.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B22 16792 bytes