Malicious PDF — malware analysis report

Static analysis result for SHA-256 3528bbf9e9dece99…

MALICIOUS

PDF

79.1 KB Created: 2021-09-19 21:14:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: add79f33efe82a0760748f06315b4f54 SHA-1: 260131e3dc52527fd5377ff452166b9648702bfc SHA-256: 3528bbf9e9dece99c0315d592b31fd4fe62d6770a19527d2cdb25da29868ffb4
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs and link farms pointing to various domains, suggesting an attempt to redirect users to malicious websites. The authoring application 'wkhtmltopdf' is noted, but the primary malicious activity appears to be the distribution of links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://archism.ru/uplcv?utm_term=iriun+webcam+app+android PDF link annotation
    • http://oppedisanorobertosrl.com/userfiles/files/6052976670.pdfIn PDF document text
    • http://mdknoodles.co/uploads/files/9619353020.pdfIn PDF document text
    • https://mdteam.se/ckfinder/userfiles/files/rakofu.pdfIn PDF document text
    • https://comptables-publics.fr/userfiles/file/wuxufezinepelabo.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/ad0ee21c0fe2737c702c190d4abb6b72/kopag.pdfIn PDF document text
    • http://www.allatpatikapecs.hu/images/file/pibuzuzefezezabi.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161366d6c4a896---12085824350.pdfIn PDF document text
    • http://gccde.com/downloads/blog/geust/files/73331131523.pdfIn PDF document text
    • http://tydafa.com/dafa/uploadfiles/20210909062103.pdfIn PDF document text
    • https://china-glass-mosaic.com/userfiles/files/20210908_113432.pdfIn PDF document text
    • https://hanyauntuktesting.com/contents/files/35815618576.pdfIn PDF document text
    • http://hattingtoemrerogsnedker.dk/userfiles/file/gemovuxujawiw.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/5130394514.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///2021090619847_762918575.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137619591702---lagazavofumi.pdfIn PDF document text
    • http://glampingcaravan.com/userfiles/file/20210907235823.pdfIn PDF document text
    • http://hotelamadeustorino.com/userfiles/files/gopesaluguzoxolir.pdfIn PDF document text
    • https://galaxy-training.com/userfiles/file/22211355907.pdfIn PDF document text
    • https://ctners.com/ckfinder/userfiles/files/kerof.pdfIn PDF document text
    • http://l-max.ru/userfiles/file/jodijejodop.pdfIn PDF document text
    • http://sungwoo-n.com/userfiles/file/fepujibeduxavifa.pdfIn PDF document text
    • https://omegaplus.bg/uploads/pages/files/45030592150.pdfIn PDF document text
    • http://enotecagaribaldi.it/userfiles/files/24693700187.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_off0000c653.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC653 21960 bytes
SHA-256: b09733813130789ee9601012d3df1e675fa51db156616340bbd73af2b1104371
font_01_sfnt_off0000feee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEEE 10640 bytes
SHA-256: 88804132b4bfc3d2f7c3c1ecf11c7818130cdc6074da0650f9e3a2064f8241f5
font_02_sfnt_off00011710.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11710 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1