Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c5c49d9be4114a8…

MALICIOUS

PDF

87.7 KB Created: 2021-09-09 15:45:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6120f9b806c93eef1862c44052194a6f SHA-1: 5254e87d9ec401941811630dada565c4751df97a SHA-256: 8c5c49d9be4114a882bb2b46656fc0b5ae81601eca4643ed0d681af99455dc84
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, characteristic of a link farm. The ML classifier strongly indicated maliciousness, and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirms the suspicious nature of these links. No scripts were extracted, but the sheer volume of disposable links suggests an attempt to manipulate search engine results or redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9765

Heuristics 4

  • 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://pokebarslo.com/uploads/files/87646495237.pdf In PDF document text
    • https://hongmao.tw/uploads/files/202109081620044864.pdfIn PDF document text
    • http://babijie.com/upload_fck/file/2021-9-2/20210902024359451930.pdfIn PDF document text
    • http://directopinion.biz/uploads/FCK_files/file/fifokezakudemowupon.pdfIn PDF document text
    • http://tochuchoinghi.org/files/20817424215.pdfIn PDF document text
    • https://winpoasia.com/ckfinder/userfiles/files/xugururulupalumek.pdfIn PDF document text
    • http://riverla.vn/uploads/userfiles/file/17595736658.pdfIn PDF document text
    • https://photopoligrafic.ru/ckfinder/userfiles/files/kapagima.pdfIn PDF document text
    • http://koppeika.ru/userfiles/file/jusebilixata.pdfIn PDF document text
    • http://de.ruben.pl/ckfinder/userfiles/files/puburas.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/161319a8fb981f---nukaxojuzopes.pdfIn PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210902_205109_104.pdfIn PDF document text
    • http://ecohouse-lab.de/userfiles/file/12771747073.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16133e2dbd536a---57446657645.pdfIn PDF document text
    • https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/79228705839.pdfIn PDF document text
    • http://safaraval.com/basefile/safaravalcom/files/80328311998.pdfIn PDF document text
    • https://portalbime.com/UploadedFiles/New/file/murupuvarekorope.pdfIn PDF document text
    • http://ptaki.info/imgekoprojekty/files/58794624162.pdfIn PDF document text
    • http://diversecityuk.com/userfiles/file/26421762240.pdfIn PDF document text
    • http://nwatchonline.com/userfiles/file/wotuvozifav.pdfIn PDF document text
    • http://wwsm-us.com/files/file/4654473686.pdfIn PDF document text
    • http://thaimassagemodel.com/ckfinder/userfiles/files/suzerol.pdfIn PDF document text
    • https://nbretail.com.vn/ckfinder/userfiles/files/letotikuxiposuwutadiduti.pdfIn PDF document text
    • http://gemculture.com/userfiles/file/pupuxejotoperutuxetidaku.pdfIn PDF document text
    • http://pretaporter-pegah.com/userfiles/file/fedepu.pdfIn PDF document text
    • http://myphamso1.net/uploads/files/27537825608.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=this+application+is+not+authorized+for+use+on+your+android+devicePDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d9b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9B1 16876 bytes
SHA-256: 33031afdd8657f0b9b638c84e518296a91ea1c1c1dcca5de613fa0a967db5be4
font_01_sfnt_off00010584.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10584 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D9B 11020 bytes
SHA-256: 82dced5191146d24364573a64421f461b16735b205211fb14148c15b30e4f395
font_03_sfnt_off0001373f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1373F 16972 bytes
SHA-256: 9ecfe7072d1d78974e16cb8cf56ff36da8e59192eebf59c61485cf4a61ce1d54