Malicious PDF — malware analysis report

Static analysis result for SHA-256 84623c88cb39dee7…

MALICIOUS

PDF

165.6 KB Created: 2021-07-28 06:42:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 5f042cab7c869754d53852cc988b0841 SHA-1: b3e6e054494a46fb8235da7f576e45e0e1cc5e61 SHA-256: 84623c88cb39dee71c317ecb63184393add44b572cef31ad2d5f84d5dabd22f5
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or are part of a link farm strategy. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated, preventing a clear understanding of its direct user-facing content, but the link farm heuristic and URL analysis are sufficient to determine its purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://animationcoach.com/userfiles/file/97856334055.pdf In PDF document text
    • http://dyweisheng.com/uploadfile/file/2021072510472773499.pdfIn PDF document text
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/058d7fa21c53ffef16ef92553b193863/63596565837.pdfIn PDF document text
    • http://noahjohnsonsark.com/clients/e/ef/ef24418f2336b9480f3353ee42fa3f58/File/17422656782.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/89240817964.pdfIn PDF document text
    • https://culturasiapamplona.com/guiarte_userfiles/files/15555242263.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/160b2f1d115870---voxunafopirixogetir.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c45f3aba8ee---81602903866.pdfIn PDF document text
    • https://anukulagrotech.com/userfiles/file/sozagixosefu.pdfIn PDF document text
    • https://cbdc.co/uploads/ckfinder/userfiles/files/vekevoxadebana.pdfIn PDF document text
    • http://ansatrans.ru/admin/ckfinder/userfiles/files/79175869735.pdfIn PDF document text
    • http://npi-management.org/ressource/site-image/files/23640130988.pdfIn PDF document text
    • https://aprilboya.com/userfiles/file/kumetepepasiw.pdfIn PDF document text
    • http://duoctruongxuan.vn/userfiles/image/file/96152226860.pdfIn PDF document text
    • http://kaushalacademy.org/ckfinder/userfiles/files/xupifovatisofuta.pdfIn PDF document text
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/ba8a8d496a496399d1a7fdb8ac723253/felotowuwajiriv.pdfIn PDF document text
    • http://www.humillacionyestrella.org/ckfinder/userfiles/files/nemutubis.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a1d328d58fa---77822114603.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4b5415e8f7---96111481936.pdfIn PDF document text
    • http://likeevent.it/writable/public/userfiles/file/55013770451.pdfIn PDF document text
    • http://www.lugashotel.com/data/editorfile/57202304532.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160bd50c56f8cc---98674540676.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/bdnhplmh4gjr5gslgc64prrv77/fuwarom.pdfIn PDF document text
    • https://pediatricpotentialsnj.com/PP/PPpng/files/loxexapebobixawe.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16100636e41ed5---18986327903.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=what+happens+in+trials+of+apollo+book+5PDF 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_off000225dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x225DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00023def.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x23DEF 18656 bytes
SHA-256: a0b4c6a36da4e82dd6f33e7dfe86aef723eed5b5f961ee49c4b11899a2400f4c
font_02_sfnt_off00026ee3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x26EE3 10816 bytes
SHA-256: 95473062f5b0114eeb6716ef07306838f47de02806feeeaa6b25df8449b0e196