Malicious PDF — malware analysis report

Static analysis result for SHA-256 424ba5c3db4f5f54…

MALICIOUS

PDF

79.0 KB Created: 2021-09-07 04:54:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 0964848808c5fff4026c517fbbb93c6c SHA-1: 5ecaf25e79cd284ea9f19977f1e7d17a698a5498 SHA-256: 424ba5c3db4f5f5440b7314f85d016c23c27ad8a224db60e4afaa3c08bd692b3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, and the document body was unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9844

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 https://ketchas.ru/uplcv?utm_term=65+mustang+auto+or+manual PDF link annotation
    • http://nhuaduongnhapkhauaz.info/upload/files/julodomuf.pdfIn PDF document text
    • http://kingsfci.com/userfiles/file/25358099239.pdfIn PDF document text
    • http://eltonltd.ru/sites/default/files/uploads/xumejugobavulejuwatolog.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/16080f68c5921f---99317593472.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/29174011854.pdfIn PDF document text
    • http://gutachterbewertung.de/userfiles/file/40816416239.pdfIn PDF document text
    • https://alamansyria.com/userfiles/file/69794726392.pdfIn PDF document text
    • http://www.biosafety.biz/ckfinder/userfiles/files/90878384885.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/r8p7j9tram5nbfvquu068pkqqb/96999931531.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160afdcc768ccf---kedufade.pdfIn PDF document text
    • http://volkshilfe-ktn.at/images/content/files/fejowawopakanusib.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607f79b72e5ec---wubimogaguvijakalofad.pdfIn PDF document text
    • https://www.hemoroidklinigi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bae196d1bb---paludesefazu.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/d9528d26acdd1fee7774f0b88abc0a3a/zujamomasozigubaj.pdfIn PDF document text
    • http://poaglasses.com/uploads/files/202109052344138947.pdfIn PDF document text
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/jmr7p7pk7nvk7sr7ag5v2agemp/44422255164.pdfIn PDF document text
    • http://www.netcorp.hu/data/editorfile/66379734588.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160cfa142b27c0---78497679941.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/ehp9himqs4h00t72f8kefdnvj6/bemono.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087ad3d28cff---xanarazibawogasud.pdfIn PDF document text
    • http://instandee.com/Images_upload/files/43494336338.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/16077ce10c2dcd---mimesobopavufog.pdfIn PDF document text
    • https://acronimocostanzo.com/userfiles/file/34433805683.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2b849487bd---90381823737.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/7tsto3a5a1f9a4tmnku1mbdfq2/41828531949.pdfIn PDF document text
    • https://blokhol.com/upload/files/zoxetuvaleloj.pdfIn PDF document text
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/c47354e6b02fc2c4fd6be0dfe083c88c/40369896720.pdfIn PDF document text
    • http://nemdanangpho.com/uploads/2021-06-23/images/files/57591164333.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_off0000d304.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD304 10532 bytes
SHA-256: 0d37f3e1416bd38ed6c2b764a0988ec11b5b150a349f8fbd11f45ae97eaae657
font_01_sfnt_off0000eb14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010326.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10326 16992 bytes
SHA-256: 04ab31f66bcdc51720280bf4045acf524e74294cb48671569da9d091cd6eecc9