Malicious PDF — malware analysis report

Static analysis result for SHA-256 c253be9d4b43bd3d…

MALICIOUS

PDF

84.7 KB Created: 2021-07-15 22:30:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 0355f6c8defb542a8a36067d71de8e94 SHA-1: 96be0b15fd828a8817f6781d245b71bd295c0be3 SHA-256: c253be9d4b43bd3d9c92043d76fa027bac903082659c2539b30c995b365ae708
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to potentially compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the nature of the embedded URLs and the heuristic firings indicate an attempt to lure users to external sites, likely for phishing or further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/s65ccpgv1iua7qac99gf9e76dt/27685756872.pdf In PDF document text
    • http://bmcnx.com/userfiles/file/53612344585.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/8941b807690cc72840ce11d693bf16e0/sevigamowatokemazer.pdfIn PDF document text
    • http://kiavysocina.cz/UserFiles/File/35149796031.pdfIn PDF document text
    • https://puntoagricoltura.it/file/tigizobapaguxekuxifigozaz.pdfIn PDF document text
    • http://ghalemdi.com/userfiles/file/89923536728.pdfIn PDF document text
    • http://gotween.com/userfiles/file///juroboludapovufuvoji.pdfIn PDF document text
    • http://renknh.com/ckupload/files/lizafobedariwa.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-5-2/20210502202221786864.pdfIn PDF document text
    • http://nuovartea.eu/userfiles/files/72824986519.pdfIn PDF document text
    • http://toyotaquangninh.org/data/dulieu/files/27383550033.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16078fb3c7a6ec---furapanejadefuzumux.pdfIn PDF document text
    • http://tasteofruraleurope.eu/upload/File/78822005185.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6abd8d4bc4---78847124938.pdfIn PDF document text
    • http://stringquartet.biz/web/images/fck/file/33127462680.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/midisulijutevitiz.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc8bf8442a---17127917429.pdfIn PDF document text
    • http://say-international.eu/userfiles/file/37628443092.pdfIn PDF document text
    • http://aci-immobilier-douai.fr/userfiles/files/53818752428.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/c1q7a1ngvldo53sicbh8os3dg7/pimonekuvunojeburezezo.pdfIn PDF document text
    • http://toyotarent.kr/FileData/ckfinder/files/20210706_18E688F8977CD154.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=performance+appraisal+literature+reviewPDF 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_off0000e85d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE85D 16840 bytes
SHA-256: 64f0483516ed5d28b1b85a86f7098c0ee9819f247d8e7a3971de1c82858b9152
font_01_sfnt_off0001140f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1140F 10892 bytes
SHA-256: 27007d3563e1a6447979206e1121dbef20ec8cccb2fc7840d8486e6ae0567d5e
font_02_sfnt_off00012d57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1