Malicious PDF — malware analysis report

Static analysis result for SHA-256 83dde768dca10f5c…

MALICIOUS

PDF

69.9 KB Created: 2021-09-19 07:05:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 0c3ad1a070506a1d7b967a0545f22af2 SHA-1: 6a97f3d0dfd4b026d08e592139fc4a21ea49b9bc SHA-256: 83dde768dca10f5c1ef03779006233a5a388e6451ee83d559c29af0ebd2ae5c7
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple external URIs suggests an attempt to lure users to potentially harmful content. No scripts were extracted, but the structure and URL patterns are consistent with a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://laborke.ru/uplcv?utm_term=head+of+ravenclaw+house+in+harry+potter PDF link annotation
    • https://mauspro.net/upload/files/gitilafaponos.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614633a1f053d---dixawosimidafo.pdfIn PDF document text
    • http://foto-recepty.sk/images/fotky/zosajimelaje.pdfIn PDF document text
    • http://bolt.fo/public_html/userfiles/files/42478662537.pdfIn PDF document text
    • https://ontech.vn/images/ckeditor/files/88158079058.pdfIn PDF document text
    • https://at2-turbo-j3t.com/contents/files/movixaxukuzilixu.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161375c0dc5e03---20226384558.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/95612500637.pdfIn PDF document text
    • http://ihanzao.com/userfiles/file/20210919083459_885968646.pdfIn PDF document text
    • http://weingut-suppan.at/files/67352967738.pdfIn PDF document text
    • https://lesura.net/userfiles/file/kitexovazune.pdfIn PDF document text
    • http://slenderclub.cz/ckfinder/userfiles/files/towigorekoxizebezosip.pdfIn PDF document text
    • http://manpukuorder.com/uploads/files/33238394973.pdfIn PDF document text
    • http://eco-building.cz/UserFiles/File/71925398929.pdfIn PDF document text
    • https://www.hippocratio.gr/ckfinder/userfiles/files/zusopom.pdfIn PDF document text
    • http://brmxn.com/userfiles/file/20210911075700_jmg984.pdfIn PDF document text
    • http://mgbig.com/upload_fck/file/2021-9-15/20210915161027653353.pdfIn PDF document text
    • http://chanhbon.vn/media/ftp/file/xapunizunovajuta.pdfIn PDF document text
    • https://sicurezzaips.it/uploads/file/xaravijufulufofepakoxit.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/dc1dsfeeeql93p8lb7jmbs2b5q/60070110587.pdfIn PDF document text
    • http://jezirka-biobazeny.cz/UserFiles/File/wepor.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/gm4oitc1c7b21ts34c6akl2qi2/vobositipev.pdfIn PDF document text
    • 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_off0000b115.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB115 15532 bytes
SHA-256: 67a84fee1034e0c0ce8cc048ab538afabb33cdd5f0e5f0b6d28b88f5ddfdfc74
font_01_sfnt_off0000d84d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD84D 11072 bytes
SHA-256: a71a0e0310eff19a1652f97a5a2c9185ae230401c42133cea8562a1feeacf13c
font_02_sfnt_off0000f20c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF20C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1