Malicious PDF — malware analysis report

Static analysis result for SHA-256 35fe2ae2d1a131e8…

MALICIOUS

PDF

88.4 KB Created: 2021-09-16 18:46:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: bc3eb531edd06dbf0565d020b6d50bba SHA-1: 1a3a504cde9165a65b6dc1b0233254e2790c6175 SHA-256: 35fe2ae2d1a131e8b2af2d802b60eb70e92904e3a2b57346f61c313df68ee8c1
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to various domains, many of which are hosted on compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL analysis suggest the PDF's primary purpose is to redirect users to external, potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://ueros.fr/admin/ckfinder/userfiles/files/24235020692.pdf In PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/b1go1ilq53c2j2eph3vlti42j1/liwas.pdfIn PDF document text
    • https://intervalhousehamilton.org/ckfinder/userfiles/files/xeraniguluralowax.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613c505752a4d---41732495644.pdfIn PDF document text
    • https://xn--80aaa1arbfjoe3bzh.xn--p1ai/data/files/51931364274.pdfIn PDF document text
    • http://schokofontaene.de/idata/69039691990.pdfIn PDF document text
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/68e54267d344930baec4fe13e56e4e63/13890643513.pdfIn PDF document text
    • https://m-isc.com/userfiles/file/53563249319.pdfIn PDF document text
    • http://yuhao-tech.com/userfiles/file/remakatesevadugis.pdfIn PDF document text
    • http://lukinserv.hu/file/nelividudaravukaritij.pdfIn PDF document text
    • https://okinawa4d.com/contents/files/70067764389.pdfIn PDF document text
    • http://icsbc.ru/fuploader/file/rosokopitixa.pdfIn PDF document text
    • http://zl369.net/userfiles/file/36444579800.pdfIn PDF document text
    • http://oprandi.it/userfiles/files/83634862787.pdfIn PDF document text
    • http://ng-sons.com/userfiles/file/83747989715.pdfIn PDF document text
    • http://www.siposferenc.hu/html/losedowi.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/695dc292c575a12dfd09c18848838d9f/11985167526.pdfIn PDF document text
    • http://deltools.com/userfiles/file/wejaxagapawux.pdfIn PDF document text
    • http://nieruchomosciklodzko.pl/files/file/vetojemomusu.pdfIn PDF document text
    • https://dianthusindustrial.com/resimler/files/metarapidazaxageradad.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161334fc6594c7---dovek.pdfIn PDF document text
    • http://matchonusa.com/uploads/files/tulenezakejikozulapet.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=best+strategy+games+for+android+2015PDF 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_off0000f5f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010e0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E0C 11248 bytes
SHA-256: f6437d4a7ce934be0be98129466344d163c6b28536d9a26e4bc83e9664e1b242
font_02_sfnt_off0001286b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1286B 16760 bytes
SHA-256: 2594466d58e9e41fa880aa03e750dbf38d1327fe7c85d30a4a15208a4084efbd