Malicious PDF — malware analysis report

Static analysis result for SHA-256 7f315c8870e4a250…

MALICIOUS

PDF

75.2 KB Created: 2021-07-02 14:13:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: a0d2921f59ca961bddf55ce54ac75fbf SHA-1: 1c43d602accb03ce299e819805fd5418f0aca0bd SHA-256: 7f315c8870e4a250634b6b5311146927ebe5ea8fbd3ad5689b2679e7ac8c4bdb
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It functions as a link farm, containing numerous embedded URLs that point to compromised websites, likely intended to lure users into phishing scams or malware downloads. The presence of multiple distinct hosts and the use of 'utm_term' parameters suggest a coordinated effort to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9790

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://coretry.ru/uplcv?utm_term=absolute+value+problems+pdf PDF link annotation
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a0fbf16aed6---zalilenotawopinokuxose.pdfIn PDF document text
    • http://mariopresto.pl/userfiles/file/17944575811.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071240579a99---gifilumurovuruzojik.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607daa652dd96---90548439034.pdfIn PDF document text
    • https://latework.cz/soubory/nesiwepepojimumelebetani.pdfIn PDF document text
    • https://jjcfurnituremaker.com/userfiles/files/kazewon.pdfIn PDF document text
    • http://aczelzalog.hu/tmp/pafilawozuwo.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160ab34aa84e2b---bowurizizevawanufomokijof.pdfIn PDF document text
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/liibv7gpeoklnkgcvtcj5hrub8/tedenufi.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16091cd9a8ffb3---12343704129.pdfIn PDF document text
    • http://bogelaipigeon.com/upload/file/51815986153.pdfIn PDF document text
    • http://geoass.eu/userfiles/files/mexijofelapi.pdfIn PDF document text
    • http://tragadsonisurat.com/ckfinder/userfiles/files/49739510433.pdfIn PDF document text
    • http://wadsoda.com/UserFiles/File/16814524660.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ceebc93c45f---76717538816.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/b8ed84b5cpqa8upmiqsdfku3b6/jatod.pdfIn PDF document text
    • http://fritz-fahrlaender.ch/download/87802638877.pdfIn PDF document text
    • http://teerosy.com/ipp/images/uploads/files/somumikawutupofijogoxa.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/18709729ea49a86580bb0e6da3a10c78/47673242502.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/ce31e4e80cf421bc63159771c242673c/bajafimaliguwu.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607eff54db4c9---ludipuwafetimivopoxaga.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0afd86aae---jajelubanagefogab.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/22567539710.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/a228424d9b6c5807cc17272a0303077f/41881017747.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/c0583a6f300f32b2b83bf494339117df/25541972014.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/038e9433854d7a2d3e7a67dca9a8eaa0/kazipibaliwi.pdfIn PDF document text
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/df851ccc33bf68a20e48724b57c201db/gezosovirapomusuw.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_off0000c4b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4B6 16232 bytes
SHA-256: d8deaae75000e02681065b875eff3f5d471c084838b25f4ae0cdc2a42b6791a4
font_01_sfnt_off0000ee90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE90 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000106a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106A7 10748 bytes
SHA-256: 4fe94e2dc7fce9b2eb7ba14856b651b6eb0645dcc2e1c56ebb15f54d5c9e223f