Malicious PDF — malware analysis report

Static analysis result for SHA-256 835516397b8fa0cf…

MALICIOUS

PDF

97.0 KB Created: 2021-07-02 23:46:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 3505fe7484fa8e36c54e2c9189bb94f5 SHA-1: a10f861ac4e2ee7f2674a95203fad7fa92036509 SHA-256: 835516397b8fa0cf25629f6573cf8f0c91df01ad989c6d4d458a587940926d3e
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress sites and other disposable hosting domains. These links likely serve as a distribution point for further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9910

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 http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7a769cd0de---xivosinelezi.pdf In PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a85a710860---37110168763.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c95b0089a8---19854903361.pdfIn PDF document text
    • https://wccia-vastu.com/wp-content/plugins/super-forms/uploads/php/files/fe6b59b2265a53f97c501eb43985b71a/54995499576.pdfIn PDF document text
    • http://kamerton.nl/clientfiles/50054755908.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608e4d432c695---29348680218.pdfIn PDF document text
    • http://kiddeefire.com/media/userfiles/files/wadogir.pdfIn PDF document text
    • https://lenaoyunlar.com/calisma2/files/uploads/kizanekewosisitinavimif.pdfIn PDF document text
    • https://opuntia.eu/wp-content/plugins/super-forms/uploads/php/files/29cf68176bca6252e74aa48d00f04e49/zafuzurama.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/9d0c09872828c67aff9557ebf715e178/33955814644.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba20ac5f68---baxeme.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/78f6a6f56e0b8253ec2c34ce8519d6b5/jonapeteg.pdfIn PDF document text
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/a20fe388fcac505aa93e46d48792c78b/zekuro.pdfIn PDF document text
    • http://bereanbaptistashton.com/clients/1/1c/1ca8668e480cca1e897b6add33210fc6/File/54515702321.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/8mcio4p3cs1to5u0oc9skfic4r/67573120453.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-5-17/20210517160008149597.pdfIn PDF document text
    • http://nextgenship.net/upload/file/20210519162138620672.pdfIn PDF document text
    • http://weddingdiy.cc/uploadfiles/files/20210606_033451_2699.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/92114023154.pdfIn PDF document text
    • http://soldresold.com/Shradhdha-Mehra/soldresold/final/ckeditorimage/files/wajavodola.pdfIn PDF document text
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090ced77691f---zuxepovabep.pdfIn PDF document text
    • http://mesterek.net/tmp/86693136917.pdfIn PDF document text
    • http://sjhrz.com/images/upload/File/58204999663.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2ade111f2c---60658518482.pdfIn PDF document text
    • http://anatolianlgs.com/userfiles/file/271898752.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=dead+or+alive+2+dreamcastPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000104c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011cd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CD3 5232 bytes
SHA-256: d3d490774376e6fa0d1a89f65d577627eee76e49c00d983bf1c9687c4bc2dfea
font_02_sfnt_off00013022.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13022 10616 bytes
SHA-256: e3733bdcc93bfa444d1c9dbafc933b99303643ae5098149bc53ffc5d2273d033
font_03_sfnt_off00014877.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14877 17368 bytes
SHA-256: 89ba6420b521060029c24a3c1d1ec719a8df87671dd56725a1e53b4557a78e8e