Malicious PDF — malware analysis report

Static analysis result for SHA-256 4121b44492c4a14a…

MALICIOUS

PDF

73.4 KB Created: 2021-09-30 10:31:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: f13db6558ac7b4b09c4720631d135bc9 SHA-1: a4d2b7da4898580df77a711c02344a31dc8c4d03 SHA-256: 4121b44492c4a14ab488c775cc2a57cb69bef2239074a1e73b5837c6c58058d4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a machine learning classifier and ClamAV, indicating malicious intent. It contains numerous external URIs and is identified as a link farm, suggesting it's designed to redirect users to potentially harmful websites. The presence of embedded URLs and the overall structure point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://chcial.ru/uplcv?utm_term=video+player+all+format+apk+pro PDF link annotation
    • http://zeroseistudio.eu/userfiles/files/32541056756.pdfIn PDF document text
    • http://inbeeldt.nl/userfiles/file/serazo.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/worekevomakiga.pdfIn PDF document text
    • http://everest-c.ru/ckfinder/userfiles/files/duxuxu.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/11637993831.pdfIn PDF document text
    • http://kimsanghun.com/upload/userfiles/file/20219121351113132.pdfIn PDF document text
    • http://gzafjc.com/uploadfile/files/21742717956.pdfIn PDF document text
    • http://kbchina.de/upload/23729084866.pdfIn PDF document text
    • http://maychamsocda.vn/images/userfiles/file/17612294038.pdfIn PDF document text
    • http://ruben.pl/ckfinder/userfiles/files/40097471286.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/9647186506.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/88870224240.pdfIn PDF document text
    • http://adbuilder.at/ckfinder/userfiles/files/39309502669.pdfIn PDF document text
    • https://kameramuzesi.com/upload/files/wiripawavunum.pdfIn PDF document text
    • http://graviroz.hu/ckfinder/userfiles/files/tixomixabipi.pdfIn PDF document text
    • http://vamaconsulting.sk/userfiles/file/25444651003.pdfIn PDF document text
    • https://crossfitbeeshark.ro/app/webroot/files/userfiles/files/pezusafus.pdfIn PDF document text
    • http://qdjshg.com/files/file/91354342964.pdfIn PDF document text
    • http://riverside-plaza.com/upload/userfile/files/18740662052.pdfIn PDF document text
    • http://alt-1c.ru/userfiles/file/gebagaxabukikixaj.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612eecb238054---vamaduxor.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/77608467489.pdfIn PDF document text
    • http://www.globalnautique.nl/upload/files/gunejajakufeme.pdfIn PDF document text
    • http://esistore.com/userfiles/file/74883404252.pdfIn PDF document text
    • https://calienglish.com/ckfinder/images_store/files/34290161949.pdfIn PDF document text
    • http://tangiahoang.vn/Images_upload/files/10866711354.pdfIn PDF document text
    • http://brbud.pl/userfiles/file/rokunodilokexuvemarox.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_off0000ba81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA81 17556 bytes
SHA-256: d5fd2e6389c30c90db04ad4f45b5af15a34820fc69db45d92340c256ef865427
font_01_sfnt_off0000e74f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE74F 10564 bytes
SHA-256: fa57b6ebfe474cd04b16a1de8355938ab3c94815e8397ccd4da85c489b32e306
font_02_sfnt_off0000ff72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF72 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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