Malicious PDF — malware analysis report

Static analysis result for SHA-256 13171b37c4033d07…

MALICIOUS

PDF

73.0 KB Created: 2021-09-08 09:22:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: cef85ecca9f082864cf3633c0a0751d3 SHA-1: a631d9b7482cd07946ef7cb5fe307b1dbe00807f SHA-256: 13171b37c4033d07792ffcbf4e2575714086222809498de5e6631cd94285aec8
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://hoaisonland.vn/upload/files/39547360152.pdf In PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/daabf42959ffe5096dc24de00c108a22/fititi.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/4a0571eddad9480242675334ebc4b60e/kewatawa.pdfIn PDF document text
    • http://xn----8sbaqfskngn1qi.xn--p1ai/userfiles/file/mimekifujegapirinotovog.pdfIn PDF document text
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/e41c16dea00bdfd20ae5a2c901539eac/fipidowigi.pdfIn PDF document text
    • https://alice-immo.com/userfiles/file/legemel.pdfIn PDF document text
    • https://xistenze.com/files/files/30721705036.pdfIn PDF document text
    • http://noithattamphuong.com/upload/files/nabasisotakix.pdfIn PDF document text
    • https://vivaldiroberto.com/img/files/mediafiles/file/nosur.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/10ccf8d1ba34d1da6b352e202585517d/99184361467.pdfIn PDF document text
    • https://alutat.com/data/file/femejop.pdfIn PDF document text
    • http://muzeumostrowiec.pl/obrazy/file/13148343254.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608861f451ba6---rutidemetemajodij.pdfIn PDF document text
    • http://leruichem.com/upload/files/witinikamanunesazerom.pdfIn PDF document text
    • http://rulife.ru/ckfinder/userfiles/files/wuvorasofuwojowuser.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/203640142060f3b55825997.pdfIn PDF document text
    • https://goldmenu.com/userfiles/file/bowesosikifopulegu.pdfIn PDF document text
    • http://accapierre.it/userfiles/files/pizekadapirotiwulufimuloj.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b091cf5ad7d---68861779348.pdfIn PDF document text
    • http://15449010.com/FileData/ckfinder/files/20210802_80084EC7506002BF.pdfIn PDF document text
    • http://profil-metall.de/content/uploads/file/73697275974.pdfIn PDF document text
    • https://e-ceramika.pl/userfiles/file/10172861877.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/16080cfa3d0c6b---wuwowosinase.pdfIn PDF document text
    • http://prplus4u.com/ckupload/files/39958382837.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=let+her+go+ukulele+tabs+pdfPDF 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_off0000ba15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA15 10872 bytes
SHA-256: e22cdc13c855b9d37e1a043363af548ecb7f75608bccf6e7b759892d7b2c66b5
font_01_sfnt_off0000d2f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2F3 16776 bytes
SHA-256: c1a3c503e7b8c10f33759261bfb86644de50bdaea50532e21acedc2b5ddb5e6b
font_02_sfnt_off0000fdcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDCD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1