Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cecb5883ea27909…

MALICIOUS

PDF

88.1 KB Created: 2021-07-30 02:23:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6807e884c615d7e6a2e34ad7d85ec80b SHA-1: 3c8c4beb7b02023750dc38894bd3a65413bcb7a2 SHA-256: 4cecb5883ea279099f2ffadffd004eee7b478185bc9ebbf7f767907fa68ef14d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning model assigned a high probability of maliciousness. Static analysis revealed numerous links pointing to compromised WordPress sites, indicating a link farm designed to host malicious content or phish users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/jaghvro6pflpm6iq12s5fp3l7p/98563504855.pdf In PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a59b0ec43a7---numaf.pdfIn PDF document text
    • http://calisnt.com/uploads/files/41232190271.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/abbol1ne4hasa3i5gkrulbv793/seriwi.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/e40471a5052c1431a85be334176e863e/tazulivegoduwekedasujeleb.pdfIn PDF document text
    • http://yaeram.com/userData/board/file/25069520978.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a8facecbbd4---71411689062.pdfIn PDF document text
    • https://baoyi-chuck.com/ckfinder/userfiles/files/23203904397.pdfIn PDF document text
    • http://www.thaiboat.net/image/upload/File/jimijajoto.pdfIn PDF document text
    • https://fibaquitaine.fr/cebatrama/userfiles/files/23436012266.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/fedozefuxos.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/7f13bc2b9e5b9073aa54c50e5bd3493d/59847368662.pdfIn PDF document text
    • http://project-lovcen.me/userfiles/file/jeberarijexakim.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606c73b41ca8d---jazawowatesotu.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d020c7c4d88---67470326871.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a429740b61---xipoxogef.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091b971499f6---95476544448.pdfIn PDF document text
    • http://hesexpo.com/img/editor/image/file/99923929956.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/afs4uhgpg1s0trhk41hse533f0/92335323606.pdfIn PDF document text
    • https://netshopnepal.com/userfiles/file/58776781481.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3a6dbe1fcfa8b6997262e6229ea22922/30230824052.pdfIn PDF document text
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/b85fba9b60d19f6fedbcb581631fc248/51796575035.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/8d91634bacfa03d14dc8a53682c5cc69/fituxesasar.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/160832d41680d3---62759754777.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=decir+tu+affirmative+commandPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f52a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF52A 17356 bytes
SHA-256: f6ac0f80871f105268b548142b5fe341f82368689ce0cd400882fa1f912099a5
font_01_sfnt_off0001216d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1216D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013984.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13984 10592 bytes
SHA-256: 690f030772758b3df50dba53b7195d3730a69fbd59598b55d87f577cf7e9db18