Malicious PDF — malware analysis report

Static analysis result for SHA-256 c495b5d2eb9971da…

MALICIOUS

PDF

75.6 KB Created: 2021-09-27 14:04:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 711ed4e587dcac92adcc990ffb57b4e5 SHA-1: 25f4980dfa56e7aac1e69b98aebdeb47d6180f66 SHA-256: c495b5d2eb9971da2533a431af09c760c5d21b3269add970eb25fbc7437ec7e1
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or malware distribution scheme. The PDF structure and embedded URLs point towards an attempt to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://crysiq.ru/uplcv?utm_term=website+android+emulator PDF link annotation
    • http://medi-sen.com/files/files/18464119382.pdfIn PDF document text
    • https://gamma-electronics-eg.com/userfiles/files/jovuviluzonubazi.pdfIn PDF document text
    • https://www.lucaslobker.com/minor/ckfinder/userfiles/files/kiratisavagewelugorufodik.pdfIn PDF document text
    • https://minipowerpack.net/upload/files/zerutuzuzuvupusaz.pdfIn PDF document text
    • https://okazionche.com/files/vetonifo.pdfIn PDF document text
    • https://piti.leaddeehub.com/userfiles/files/fatokisasavepoxelew.pdfIn PDF document text
    • http://auxerretv.com/content/public/file/47645076686.pdfIn PDF document text
    • https://lexcyberia.com/userfiles/files/xigexozilokaduv.pdfIn PDF document text
    • https://phunhai.net/upload/files/nufenupopapakej.pdfIn PDF document text
    • http://tdbakademi.org/userfiles/files/84232273506.pdfIn PDF document text
    • https://cupanghitam.com/contents/files/96511184878.pdfIn PDF document text
    • https://psg66.ru/admin/ckfinder/userfiles/files/nagisebakoruwikas.pdfIn PDF document text
    • https://10playsolutions.com/clients/softklk/documents/_articles_/file/24215476348.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16150b7681bcbc---fipixu.pdfIn PDF document text
    • http://woori-tour.kr/FileData/ckfinder/files/20210925_33CA03F7A37F424C.pdfIn PDF document text
    • https://pingthye.com/userfiles/files/tavagi.pdfIn PDF document text
    • http://zenithmetals.com/files/66888942573.pdfIn PDF document text
    • http://cnex.cc/images/blog/file/64132146334.pdfIn PDF document text
    • http://praguetransfer.com/files/file/wifogak.pdfIn PDF document text
    • http://sva-jeanroze.com/xmedia/file/jiwejul.pdfIn PDF document text
    • https://chsins.tw/uploads/files/202109212115232598.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615127b5e4845---2412704158.pdfIn PDF document text
    • http://gallery4walls.com/upload/editer/file/57758817366.pdfIn PDF document text
    • https://atlaskvartir.ua/data/uploads/files/vokev.pdfIn PDF document text
    • https://www.tocbirsen.org.tr/ckfinder/userfiles/files/tadikumike.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_off0000bfc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFC4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d7d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7D6 18944 bytes
SHA-256: 40c86f97e04be42593e0ad8b9e669eaa4e94b91bc8c609f323aa5453e1384cd0
font_02_sfnt_off0001083b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1083B 10644 bytes
SHA-256: 44d683793240809709f5322394e3845fa480862e1b238896e76dff5ecc1a5307