Malicious PDF — malware analysis report

Static analysis result for SHA-256 772683bff08aa3fc…

MALICIOUS

PDF

83.3 KB Created: 2021-09-11 07:11:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 8e2491b4f913125b0ae0566f08dca7d0 SHA-1: 66af3500fcafe95c7dcfc1cb69094859b67c258f SHA-256: 772683bff08aa3fc0ba35e298456bae7dc71c0ff29e4309df68b69115ade2266
156 Risk Score

Malware Insights

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

The file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs that form a link farm, with several pointing to compromised WordPress sites or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of these links and the overall structure strongly indicate an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://crysiq.ru/uplcv?utm_term=gta+san+andreas+free+game+download+for+mobile PDF link annotation
    • http://vecsecity.info/editor_up/41306083646.pdfIn PDF document text
    • http://oskarmak.com/userfiles/file/volofobusobaf.pdfIn PDF document text
    • http://ascensionchina.com/userfiles/file/libilagasepokijexev.pdfIn PDF document text
    • https://brakos.it/file/gipafalivilezazoxafego.pdfIn PDF document text
    • http://live-lessons.net/lcj/web/uploads/assets/file/genufidaxuxasulun.pdfIn PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/d2b3d11df33db04084b9682f16222c0d/96215509597.pdfIn PDF document text
    • https://theurbanthinktank.com/files/59422496270.pdfIn PDF document text
    • http://queenart.kr/userData/board/file/5518604161.pdfIn PDF document text
    • https://visualarchive.bg/files/buxelibagozuzemugo.pdfIn PDF document text
    • http://mrhobbscoffee.com/images/uploads/file/55523227227.pdfIn PDF document text
    • http://edeins.com/userfiles/file/wutugebofojodowaxufeza.pdfIn PDF document text
    • https://thuhuonglacquer.com/uploads/news_file/47999565250.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/febonenivifewige.pdfIn PDF document text
    • http://vcelari.naceradec.cz/includes/ckfinder/userfiles/files/mumafakefokena.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/qi6vlc46g2fikmltd6lo8k10i1/bifor.pdfIn PDF document text
    • https://tipresentoio.it/images/file/xuwobowanivosemubara.pdfIn PDF document text
    • http://pnlestari.com/visitbali/image/files/tidawa.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/dea0a5d22b9b6566d7d33d687b630d50/7122459024.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/5405dc5523a350ea70528a131a43d283/25426214012.pdfIn PDF document text
    • http://kleni.cz/userfiles/file/69659484995.pdfIn PDF document text
    • https://mediaget.ru/userfiles/files/40671548563.pdfIn PDF document text
    • http://getvisa.ru/images/File/12538089641.pdfIn PDF document text
    • https://esportenerd.com/app/webroot/ckfinder/userfiles/files/82915035399.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_off0000dc16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC16 18940 bytes
SHA-256: dd344a67a5b8487aa4a9351cb5e5c7f45526676ece68bfba7fa7cf3c5a925938
font_01_sfnt_off00010db1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000125c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125C8 10964 bytes
SHA-256: aecf51e900252ca2bfe8c8a1100678dd8a57d1bd61b15345e530fbeb449635f6