Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a40cd7f2e3d7d73…

MALICIOUS

PDF

79.8 KB Created: 2021-09-11 23:58:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: fe91272ba02234a6884cb3fa35650cdb SHA-1: 6704b9d2cc92e7680ee20133cd3d5cc7a1056d5d SHA-256: 3a40cd7f2e3d7d731b437634ca0ec8146e9fbdabc08ea1eaded3002f42daa71a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to unknown domains, and is flagged as a link farm on disposable hosting. This suggests the document is designed to redirect users to potentially malicious sites, likely for phishing or malware delivery, aligning with the Spearphishing Attachment technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://bczenekar.hu/files/file/gadamatasagawaberesama.pdf In PDF document text
    • http://ambvet-trefontane.eu/userfiles/files/24811679132.pdfIn PDF document text
    • http://leeclinic.kr/userData/board/file/nonadavid.pdfIn PDF document text
    • http://win-sonic.com/ck_imgs/files/26157867559.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/favukejasonijomavebuxa.pdfIn PDF document text
    • https://paymentor.nl/uploads/file/75478374238.pdfIn PDF document text
    • https://campermagazine.tv/public/file/50798560210.pdfIn PDF document text
    • https://floresdeserrezuela.com/aym_image/files/fudenofepevenudaw.pdfIn PDF document text
    • http://khunghinhdepphuctin.com/media/ftp/file/madiwebuzejokigaxarugufo.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/16131dda34a7c1---56835665190.pdfIn PDF document text
    • http://schokozentrale.de/idata/31734240994.pdfIn PDF document text
    • http://telegid.tv/userfiles/files/wuxubafepuzirusobog.pdfIn PDF document text
    • http://phuongdonggolf.vn/app/webroot/uploads/files/80142815283.pdfIn PDF document text
    • http://montaze.org/democms/userfiles/file/vomewomuzafasubusoxasilam.pdfIn PDF document text
    • http://inbiosa.eu/static/cfiles/files/zidolumitukavo.pdfIn PDF document text
    • https://commonlawhouse.in/userfiles/file/ginoxisofu.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/89769606123.pdfIn PDF document text
    • http://vuason.vn/upload/files/wufopenijogiwitefifikija.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613075f954807---vivamorotekok.pdfIn PDF document text
    • https://dentalrud.com/userfiles/file/99701186797.pdfIn PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/wozewobanumitinekowake.pdfIn PDF document text
    • https://stop-remont.ru/ckfinder/userfiles/files/66830131138.pdfIn PDF document text
    • http://trieuduong.com/images/Download/41642994477.pdfIn PDF document text
    • http://fetogram.ir/images/upload/files/xikobonuwiximogudusaduv.pdfIn PDF document text
    • http://ngor2-3.com/file_media/file_image/file/64755445267.pdfIn PDF document text
    • http://bluestandard.pl/ckfinder/userfiles/files/mejejivurodosapimirez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=change+app+notification+sound+androidPDF 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_off0000d384.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD384 10984 bytes
SHA-256: afd0d171d6fdefc4da74a87cc4704287997cb68b4717a46e8fd2ae7f3e294f07
font_01_sfnt_off0000eccb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECCB 17144 bytes
SHA-256: c2f034fe8f12d2e911a0998f69176b69307f36609a1784eabe9c82e1ba6ca348
font_02_sfnt_off0001198e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1198E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1