Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4739e9b27629d9b…

MALICIOUS

PDF

76.7 KB Created: 2021-09-08 02:24:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 490e765a26b85f75d38221198f6c7cbe SHA-1: 8d6c96e00df4593c2ff9c8643a7c16464b0f417b SHA-256: b4739e9b27629d9b3c036f762e813703d8243e7677339543a6ae486d71f2b814
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://krisoc.ru/uplcv?utm_term=liver+gross+anatomy+pdf
    • http://passaicvalleyclassof1957.com/clients/44362/File/68144359709.pdf
    • https://xehowo24h.com/images/ckeditor/files/11622964856.pdf
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608445941d41d---36330224204.pdf
    • http://fizjoactiv.eu/Upload/file/82426282465.pdf
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f79bcb45c84---degizojom.pdf
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608be0be6c4ae---73219052866.pdf
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/160911b65b0934---29260353047.pdf
    • http://mya1fc.com/files/ckuploads/files/19397288485.pdf
    • http://all-paca.com/ckeditor/ckfinder/core/connector/php/uploads/files/giwore.pdf
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16084c1aa47a1a---2490599289.pdf
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/8471f59e35b1086f756a4ee16eb37ed8/8693432502.pdf
    • http://tipiland.net/upload/file/25668752413.pdf
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/a303c582a6ec2cdee4a6f7bc65ba85a6/lesere.pdf
    • http://www.pibmg.com.br/ckfinder/userfiles/files/files/lovuxazekisisefowujufusu.pdf
    • http://wgadget.com/file_media/file_image/file/86206920948.pdf
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/990b1a4753c45aedfdc1fa0cc672eb54/pepakofuxeguvej.pdf
    • http://kovove-ploty-brany-zabradli.cz/UserFiles/File/90715444055.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/2a0f6463548cd4dec86ee549a923448b/lodevuwutowidukitafowetem.pdf
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608c54c1adab8---dajotebepajewida.pdf
    • http://erisalaw-chicago.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rogupofudazamozalodetud.pdf
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b5d57b60db4---penamifonomajawakoxuzile.pdf
    • http://yorkiematch.com/clients/6/65/653dc45b8f6063886304ac4260dbb99c/File/zozela.pdf
    • http://arohitourandtravels.com/userfiles/file/zowawikoveximiwase.pdf
    • http://potlista.com/file/files/redarujovit.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_off0000c84a.bin
8ee153e1a962eeb9faf0d19857b542d2f47daaa56306cd78ef4b7f35512ae3da
pdf-font-stream PDF embedded font (sfnt) at offset 0xC84A 10932 bytes
font_01_sfnt_off0000e170.bin
8d0de013117bd86fa4e692ef886976cb58a5320705bd1a31d1a733a25c67eec3
pdf-font-stream PDF embedded font (sfnt) at offset 0xE170 17136 bytes
font_02_sfnt_off00010db6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB6 16792 bytes