Malicious PDF — malware analysis report

Static analysis result for SHA-256 c55da5ae3684d92a…

MALICIOUS

PDF

76.1 KB Created: 2021-06-09 21:03:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: a1b18cc12082deb67208e61e25751752 SHA-1: 444fbb1215e0d5fc4438b8d49eb767012e5537d8 SHA-256: c55da5ae3684d92a69167dd6a705bf0dd2cd1dcc14e8cfaf79a76b93b5f9e856
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://philabc.ru/uplcv?utm_term=download+8+ball+pool+mod+apk+unlimited+coins PDF link annotation
    • http://innotec-industrie.be/userfiles/file/zalepirobo.pdfIn PDF document text
    • http://pizzeria-millemiglia.de/app/webroot/img/editor/file/88400422426.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/tajixagimotalake.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/butotifeloxilevevu.pdfIn PDF document text
    • https://islandsvefir.is/wp-content/plugins/super-forms/uploads/php/files/q4fbnk8i7aef4slrmaa3iedj6s/nugupofijogadit.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160870b9e80f33---nawobedakawonurob.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/d1fde6cacceea8e89087a091861b8bab/jedazurofivibemudawu.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/c34c140866d846cf9572fd1bad10fe56/femipaxodaxugufosus.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608dc01dbce34---rademaseruvumekogiwasut.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/2158593b88670c46d90b7bb23a88a944/64584036027.pdfIn PDF document text
    • http://csc025.com/userfiles/file/20210607102355_epx42m.pdfIn PDF document text
    • http://georgekoldun.com/var/upload/file/41261660350.pdfIn PDF document text
    • http://bakoca.hu/files/file/40231074851.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160716885e3e5b---99435713494.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/jq2l94mt8q4jh0uokiscn1osqe/98997673983.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/nd08v7a14f3b1kvpu8cfo1dum2/vibewesu.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/nkohmaq445lls99uieibpokmm4/56891947024.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e930.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE930 5612 bytes
SHA-256: d1a7fcdf64dcc9eeee096c5f5550c90321dc8c0ab087053205bef3eb3c32c251
font_01_sfnt_off0000fc4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC4B 11004 bytes
SHA-256: a808078d2513d8971e9dd1727b9807c89acf22f1ee55676ae9b57674062b7ce6