Malicious PDF — malware analysis report

Static analysis result for SHA-256 a71bb64834acc54d…

MALICIOUS

PDF

89.0 KB Created: 2021-10-13 01:05:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 2c1af79a9dc46f924b896b3d2bc10db5 SHA-1: 1af7ba1e7af4853b6d7f92f80d7ef99cc2a7a798 SHA-256: a71bb64834acc54d0262b3d4e0858f09524159230efddad968e4f3338ef0c1e9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs pointing to disposable domains, indicating a link farm designed to obscure the ultimate destination. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically calls out this behavior, suggesting a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://addisonplaza.abwingsmd.com/uploads/files/parinoroxulut.pdf In PDF document text
    • https://27061010.com/uploads/files/202109260055322340.pdfIn PDF document text
    • http://sake2metustin.com/uploads/files/kususov.pdfIn PDF document text
    • http://usefchina.com/uploadfile/file///2021091103314280.pdfIn PDF document text
    • https://webrekruit.com/php_codes/Scott/VieauAssociates/code/userfiles/file/juvosinisodetumeloziwu.pdfIn PDF document text
    • http://bandbaajabarat.com/ci/userfiles/files/61464118027.pdfIn PDF document text
    • http://grupafurman.pl/!mag2011/userfiles/file/33389777395.pdfIn PDF document text
    • https://krusomying.com/data/file/soxobuluzojopofiji.pdfIn PDF document text
    • http://gzcaifeilai.com/ckfinder/userfiles/files/202110101022196662.pdfIn PDF document text
    • https://gmnavarra.es/ckeditor/files/kegexuvelonokodeletigov.pdfIn PDF document text
    • https://fortworthdental.net/cmsCart/upload/file/13245933401.pdfIn PDF document text
    • https://consultingexpert.eu/fckeditor/userfiles/file/72840694058.pdfIn PDF document text
    • http://griesvoegwerken.nl/UserFiles/file/rarafujeruxupali.pdfIn PDF document text
    • https://careerroots.net/ckfinder/userfiles/files/virojof.pdfIn PDF document text
    • http://sevgineslianaokulu.com/ckfinder/core/connector/php/uploads/files/govefalufikogasavufosuwox.pdfIn PDF document text
    • http://metroboxservices.com/upload/ckimage/files/6147330895.pdfIn PDF document text
    • https://duproject.com/uploadEditor/files/63635203110.pdfIn PDF document text
    • https://khangle.vn/uploads/images/files/nesanebaza.pdfIn PDF document text
    • http://alemotta.com/resources/original/file/xemazopeledozusifijevumi.pdfIn PDF document text
    • http://lhdrum.com/User_File/UpFile/file/20210909035604_ODQzNjEyOTY4NDU=.pdfIn PDF document text
    • https://heritran.vn/uploads/news_file/9458830407.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/7749a3e7682fe1ce65adca9684a710fe/bijikonekaroxowozunutugi.pdfIn PDF document text
    • http://luxmeterthai.com/ckfinder/userfiles/files/27965460796.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/4dZi1sgP-vI/uplcv?utm_term=marky+mark+new+kids+on+the+blockPDF 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_off0000f107.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF107 19952 bytes
SHA-256: a6b1a647c35a729fcd4f7641d9a3180a0d004544b93f570de73c9ef82bfc2716
font_01_sfnt_off000125cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125CD 11060 bytes
SHA-256: 16f742850367db17156fd1f7a3a42108e86b358aa60e2d492fa81dc7f2f443ef
font_02_sfnt_off00013f72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F72 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1