Malicious PDF — malware analysis report

Static analysis result for SHA-256 841343cc4190a7db…

MALICIOUS

PDF

91.0 KB Created: 2021-08-25 05:44:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 28a4b4ca0cff5f54ddaf7008fda78ce8 SHA-1: 8feeac9fda10a303d8945e189396257de580b48e SHA-256: 841343cc4190a7db268481b7cd4e3adc7d14fe20089b280161c7dd1a6b08f5c4
156 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate malicious intent. The PDF contains numerous links to compromised websites, many hosted on disposable domains and utilizing common CMS vulnerabilities, suggesting a phishing or malware distribution campaign. The presence of embedded URLs and the nature of the heuristics point towards exploitation of PDF vulnerabilities to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://garglob.ru/uplcv?utm_term=what+should+i+learn
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/7i6q89t81cdku4u9hvt9jqqe9q/58504581629.pdf
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2044d2f7ec---23397877498.pdf
    • https://fminterativa.net/cms/plugins/ckfinder/userfiles/files/xemibado.pdf
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/5d4c4562602fb3252ab5bb27f0dc90f4/68699329107.pdf
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/1tq7givjctvcvlusq8f6m0kmfn/50403781690.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609d1ab2071de---77110191373.pdf
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161068d188c508---35520972026.pdf
    • http://sportingclubalbinia.eu/userfiles/files/63356139686.pdf
    • http://kibbkw.com/uploads/file/70540176324.pdf
    • http://fitviewer.info/files/file/zukejevobudusol.pdf
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6a9b1628fb---gugave.pdf
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c8cc4f403b---gadelomusenanutekaxidu.pdf
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/ef01c6b9e6e1383a3628bdd470f8d7d4/78900048975.pdf
    • http://vivatbacchus.hu/files/file/xagaxaxivuteze.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/73ee49069080c75c6f1c63b105a4788f/44793417427.pdf
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/289bfb9bcf9c8c5cf543067297959d63/nixikixobidopubo.pdf
    • http://wadsoda.com/UserFiles/File/562174104.pdf
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/zifosawanif.pdf
    • http://aptekarynek.pl/zdjecia/fck/file/35566880588.pdf
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/93100d3a2dd4155869457cbb7dba2717/59991204783.pdf
    • https://earplighting.com/wp-content/plugins/super-forms/uploads/php/files/8520beb65701615f51ba165bf0bdba66/tekavuxeboxam.pdf
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7e968e5f2c---8793670147.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_off00010133.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10133 16792 bytes
font_01_sfnt_off0001194a.bin
13c4665c7b73c4b0f6b419afbcdfa13f29829bf8490f5372f724e9af08b3accb
pdf-font-stream PDF embedded font (sfnt) at offset 0x1194A 10436 bytes
font_02_sfnt_off000130f0.bin
f495ddbe7125866be26b9511f2dee712a3e904a63c54c17326673d594308d9ed
pdf-font-stream PDF embedded font (sfnt) at offset 0x130F0 17228 bytes