Malicious PDF — malware analysis report

Static analysis result for SHA-256 137d9eb8f1e6e02c…

MALICIOUS

PDF

78.1 KB Created: 2021-09-06 21:51:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4dca7c4834939a8e2a35367dad958529 SHA-1: 9914da4744a2266671728e9a3f551c8609a89019 SHA-256: 137d9eb8f1e6e02cf3e66282c6ea076e4fd210ccae6c8a766399edbbac284017
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a phishing or spamming campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://vegan-eshop.cz/data/file/98581310898.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe0b4e1de5---15966074514.pdf
    • http://jhsclassof63.com/clients/c/c8/c8cc7cee7579ddcd469b669c0eb172d8/File/36290982819.pdf
    • http://mamnonlittlesun.com/upload/files/miduvujeronevodel.pdf
    • http://casinodanmarkjackpot.dk/userfiles/file/berafosogufur.pdf
    • http://carrozzeriardue.it/userfiles/files/16948151127.pdf
    • https://blokhol.com/upload/files/16974984900.pdf
    • http://chinahongji.com/d/files/rasafodedaj.pdf
    • https://optical-axis.com/uploads/files/202108161820382086.pdf
    • https://digicpictures.com/downloads/zusiwifamakevon.pdf
    • http://bumsnab.ru/uploads/files/vobefisenalonatetebovag.pdf
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab2282567e1---67043681952.pdf
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/9d403c5da7a588794a6c32909b93d2d4/sodajerevuzubeza.pdf
    • https://betenrealestate.com/sites/default/files/file/16692370508.pdf
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b3640235f60---fogusidigepumavepon.pdf
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/56d91ba7788e44e9b05f7755df8a6d56/76472025487.pdf
    • https://nhaccugiare24h.com/uploads/userfiles/file/votonibebizaje.pdf
    • https://ka-base.no/images_content/file/mudezekawuvitowuziden.pdf
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607526dbb38e5---97138095449.pdf
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/aaadd14e6fd562c127f92b9dbe0ea0ff/jurulu.pdf
    • http://xn--80ab1a9a.xn--p1ai/sadm_files/vubavapebuzarulanipoli.pdf
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/a4d2b3ee79b03396c17b9748240a5a5e/16959846839.pdf
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084316b79390---kagumimibu.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=ctevt+entrance+question+bank+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_off0000c961.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC961 16792 bytes
font_01_sfnt_off0000e178.bin
6ae3dca46b4e4d4899d2cb8f4291c3972bbd64f3b0e500f8a6e32f106d1b4b8e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE178 11144 bytes
font_02_sfnt_off0000fb48.bin
b0766e6e755ecb1b7b081c2c142e53d2f28f4bcacaaac38ecdf44c91aa6a7a4d
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB48 18220 bytes