Malicious PDF — malware analysis report

Static analysis result for SHA-256 fdca6bfe8338d158…

MALICIOUS

PDF

106.4 KB Created: 2021-07-02 15:03:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 36469d966f9d7cf3e2572719f9aaa75a SHA-1: 3e14a66973781e2c7a40b8b78ff26a9ef908c881 SHA-256: fdca6bfe8338d158db51516dbbb06c8940121b42a8542566fea25b43d7d26510
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress installations, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded URLs are the primary indicators of compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9773

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://medvor.ru/uplcv?utm_term=sentence+with+reuse PDF link annotation
    • https://nowackleverkusen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a9e51701c99---55861286719.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16094d84f0c1a7---87356978472.pdfIn PDF document text
    • http://studiocalcinoni.com/userfiles/files/wixametogawilenegagotig.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7fee3a511c62d8c390f506548d7cdfdb/16215695118.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad1ff6ef5a3---mulififemu.pdfIn PDF document text
    • http://sethhukumchandschool.com/userfiles/file/6682776428.pdfIn PDF document text
    • https://communeouchamps.fr/userfiles/file/nimoxowip.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ddb5c3edd8---90942380401.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7281586cf9---rawikakisew.pdfIn PDF document text
    • http://aitrans.org/UploadFile/file/F1202106210947426345.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ac1391e7f72---27070427855.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/67e5187581364d2fa42885b12bb8f471/14346618363.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1608d2e987d568---todutuximewo.pdfIn PDF document text
    • http://arebiatours.com/uploads/files/gumexeredo.pdfIn PDF document text
    • http://hzzxtl.com/UploadFile/file/20210623144808802.pdfIn PDF document text
    • https://rmp-familienanzeigen.de/cms/files/24687631579.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160cf5a020e1cd---kipiwoxoxudewa.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071ce8daf5a7---zigowusupadibisixatejubip.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160ab55c16fe31---73955134083.pdfIn PDF document text
    • http://sobsai.com/ckfinder/userfiles/files/zikobufikupajefaxol.pdfIn PDF document text
    • https://fotobolfestmeny.hu/mvc/userfiles/file/tejesemebagu.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/1bd90345a5cb5d418fc1500aca1df24d/nexanitatowene.pdfIn PDF document text
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/igsg4ffqfi47bb5tik4k3lh9bg/xeboges.pdfIn PDF document text
    • http://medtek.vn/storage/file/50144651749.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/16096b989ed884---zizupu.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160882f89b42aa---ralanimikekederinawetosu.pdfIn PDF document text
    • http://analogsys.com/uploaded/file/14500780326090e85d186c6.pdfIn PDF document text
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160d9ca1a4a980---xizufebemelapisepasekazut.pdfIn PDF document text
    • 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_off00013f81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F81 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00015793.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15793 17012 bytes
SHA-256: 19f16a19508f64ab9773c3a03242a516803213f2997e8e95acd5c7eaec6308e7
font_02_sfnt_off00018390.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18390 10260 bytes
SHA-256: d80e98b1cc37a8f22e69c9c374bedb3ce5ef658b6227a075cc46b5aa17767c50