Malicious PDF — malware analysis report

Static analysis result for SHA-256 83910ac553e4047c…

MALICIOUS

PDF

71.2 KB Created: 2021-09-28 03:48:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 877b1491a5a50652c8b6518a29cc5049 SHA-1: 1a68684dd528bb8d8487ca5d08c6a0175bde128d SHA-256: 83910ac553e4047cbb9ae8074bf63c85bbaf5bd4d1627e8d6887e6f15b0b6e3b
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads or disposable domains. The embedded URLs suggest an attempt to lead users to phishing pages or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://motorlustor.net/userfiles/file/61814683143.pdf In PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d0ba0b3e93---belizobidosari.pdfIn PDF document text
    • http://www.tivafa.hu/upload/file/89681577240.pdfIn PDF document text
    • http://hkalc.com/userfiles/69169491178.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/090531418488.pdfIn PDF document text
    • http://hoangnamjsc.com/upload/files/50292709797.pdfIn PDF document text
    • http://kompassztuki.pl/Image/files/tijevafu.pdfIn PDF document text
    • https://magnumattachments.com/ckfinder/userfiles/Files/34855052150.pdfIn PDF document text
    • http://kkagro.com/media/images/upload/file/56128246118.pdfIn PDF document text
    • http://slesnick.net/userfiles/files/73862087859.pdfIn PDF document text
    • http://svazekobciorlice.cz/userfiles/file/wevubo.pdfIn PDF document text
    • https://delaneyllc.cfonewsletter.com/ckfinder/userfiles/files/2957156462.pdfIn PDF document text
    • http://saaretravel.ee/images/file/4376428501.pdfIn PDF document text
    • http://bunny888.com/ckfinder/userfiles/files/64315488996.pdfIn PDF document text
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/suvazagutaxodezezavamasot.pdfIn PDF document text
    • https://miminku3.com/contents/files/futizo.pdfIn PDF document text
    • https://shivajigrihnirman.com/singhania/downloads/file/wisupobuw.pdfIn PDF document text
    • http://elencostruzioni.it/userfiles/files/teletajajudegatoga.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b7e1e12c5d---zamazovavigakowipex.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134a14f607d1---moxut.pdfIn PDF document text
    • http://alwaditrading.com/userfiles/files/38079825497.pdfIn PDF document text
    • http://moscowfashion.net/content/xuploadimages/file/8239132883.pdfIn PDF document text
    • http://ebslang.net/_UploadFile/Images/file/kobugerojudufugavib.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=crash+bandicoot+ios+release+datePDF link annotation
    • http://irodori.kir.jp/files/file/63868393023.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_off0000b257.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB257 17144 bytes
SHA-256: bed160933d2121e8f0d7bdf0d93f2e81790657c83dd233c63a72517cf808c1c4
font_01_sfnt_off0000de94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f6ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6AB 10640 bytes
SHA-256: 9c6a272c0a902ba0f25455272c788ab1403dde00de87ea2a70ed986b974e42d2