Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb4a8196e7781c75…

MALICIOUS

PDF

84.0 KB Created: 2021-06-26 00:57:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b39384e9a53d75df12d7aa0dcdc39048 SHA-1: ace671803c10a36ae84369addfebb839b12ad62d SHA-256: cb4a8196e7781c751e0c41c47584622b0f691198c76f7c6cbe4f7278c165a130
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or SEO manipulation scheme. No scripts were extracted, but the embedded URLs are the primary indicators of compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/a3c66254a10005fc4441defec051c939/96301358515.pdf
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/4b8075d9fe6df7b688dc6b9db2d2960f/zonovazidadut.pdf
    • https://avigailpekelman.com/sites/default/files/file/89804489781.pdf
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607afb7068124---87232126212.pdf
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b84207e56ab---tagivijakowubusemajuda.pdf
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c29345ae6a1---laravaxuviruregosusikibim.pdf
    • https://partnyor.az/userfiles/file/webuve.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160d1bf06c571d---zabatokejap.pdf
    • http://ourhkg.com/UPFILE/userfiles/files/wikelerogenowilido.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/ceib9ru5kq8clmlafaptaf8fb4/wetolabomezezafoketisup.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abfed8756a7---8436815791.pdf
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5d0d4d170---9918196274.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b18387185c---24487820925.pdf
    • http://lueckerreunion2020.com/clients/e/eb/eba09433058400eda594a485f9004317/File/1717172890.pdf
    • http://dent-pro.cz/pic/file/83512161549.pdf
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/pt2s6lqp461m002m6n3b8as272/xapuzuxofevogobidapeziwi.pdf
    • http://www.cenlaenvironmental.com/siteuploads/editorimg/file/rufuwuredobasu.pdf
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f61c325460---46757921125.pdf
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/lh6dmq33q0lla60kulo43fgf77/bekefomojejinuvex.pdf
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d32be20ff0---76626208375.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=100+most+used+verbs+in+french
    • 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_off0000e590.bin
7c81f8aeca4337b6b471f34ad3e6eb811fa91a0b10180c03dad17f8702101367
pdf-font-stream PDF embedded font (sfnt) at offset 0xE590 17744 bytes
font_01_sfnt_off000111cd.bin
ce290e63cf68f13a48467b2d05411847a16651c0704d361753573ce2e9d8d1b4
pdf-font-stream PDF embedded font (sfnt) at offset 0x111CD 10916 bytes
font_02_sfnt_off00012ae9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12AE9 16792 bytes