Malicious PDF — malware analysis report

Static analysis result for SHA-256 a50d1bd668b5b8fb…

MALICIOUS

PDF

75.6 KB Created: 2021-09-28 06:44:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 69361a802e00289a86a96bb2cc0dc55b SHA-1: bc8019ddb1255062e7b251a0d878d3706788a26a SHA-256: a50d1bd668b5b8fb0f2a03e8769a0856e205db98b18820546b1d1425bdd8825e
126 Risk Score

Malware Insights

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

The PDF contains a high number of external links, many pointing to other PDF files, indicating a link farm or distribution mechanism. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The embedded links and the nature of the PDF suggest it's part of a larger campaign to direct users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 http://dyglas.com/userData/board/file/duzapubadu.pdf In PDF document text
    • http://yogo110.com/userfiles/file/42904740939.pdfIn PDF document text
    • http://zap-interactive.com/uploads/files/segewu.pdfIn PDF document text
    • http://rebizplus.com/userfiles/file/kusefozoruduwupememap.pdfIn PDF document text
    • http://recuva.kr/upload/fck_img/1632776659/file/27601928458.pdfIn PDF document text
    • http://soft-pro.hr/upload/datoteke/77242349808.pdfIn PDF document text
    • http://creativetechno.in/userfiles/file/31077723231.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///34776019194.pdfIn PDF document text
    • http://merklink.nl/site/data/ws/files/86296351861.pdfIn PDF document text
    • https://iword.de/userfiles/file/piwanebamisowukepoponamon.pdfIn PDF document text
    • https://ostrichtours.com/ckfinder/userfiles/files/pitekodunomitibuzo.pdfIn PDF document text
    • https://www.info-service.com.tw/plugin/ckeditor/ckfinder/userfiles/files/53345669920.pdfIn PDF document text
    • http://kusistoconstruction.com/userfiles/file/teromipojunivemekavi.pdfIn PDF document text
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/kupiladawikawegunebug.pdfIn PDF document text
    • https://ochronaskory.pl/pliki_user/File/kurikaduwoxeretukokudo.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135dd9900c01---gosewepasamuvor.pdfIn PDF document text
    • https://amadesafar.ir/basefile/amadesafarir/files/tenob.pdfIn PDF document text
    • http://klsele.com/userfiles/file/1632663793.pdfIn PDF document text
    • http://hzxf.com/images/upload/File/pogibofumurolif.pdfIn PDF document text
    • https://techlan.pl/files/file/61464532527.pdfIn PDF document text
    • http://erbamedica.org/userfiles/files/dasitowamu.pdfIn PDF document text
    • http://gaziogluenerji.com/images_upload/files/37253032849.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=pok%C3%A9mon+red+emulatorPDF 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_off0000bc19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC19 20096 bytes
SHA-256: 7e86037b33bda75ad6650cfdf90123637c2b103171805c382fa8bfe7f192ddc5
font_01_sfnt_off0000f017.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF017 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001082e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1082E 10496 bytes
SHA-256: 8265168439ba7ea652291b89fed01a9606d013a3af6ba4e6de61b3c437d6e51c