Malicious PDF — malware analysis report

Static analysis result for SHA-256 a897202a7c18d644…

MALICIOUS

PDF

88.6 KB Created: 2021-09-17 08:54:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 31de5dc853a2e08a79dff22c562fe24d SHA-1: 7083ae548203cb62ed80bdcff4afed6ac5e6bcb1 SHA-256: a897202a7c18d644c7276f1c27a78580e381dae2e921610116eb3d4730cf4c43
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous external links, many of which point to other PDF files hosted on various domains, suggesting a link farm or redirection mechanism. While no scripts were explicitly extracted, the PDF structure and the presence of external URIs are indicative of techniques used for phishing or malware distribution, likely involving a spearphishing attachment as the initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://gulfapex.com/uploads/file/fifonebuboxijexopuxilolig.pdf In PDF document text
    • https://nulifeus.com/~nulife/userfiles/file/woxakutupot.pdfIn PDF document text
    • http://eska-lift.ru/userfiles/file/wuwaxogasupaxona.pdfIn PDF document text
    • http://youandisagenix.com/ckfinder/userfiles/files/86181132420.pdfIn PDF document text
    • http://kleinschadenexperte.com/userfiles/file/gerodewixadasafigutowoba.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/7174899941.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/51575028476.pdfIn PDF document text
    • http://tw-echen.com/uploads/files/202109040851141587.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613bbe487b779---98972446374.pdfIn PDF document text
    • https://guruamardaspublicschool.com/userfiles/files/pigujeseji.pdfIn PDF document text
    • http://dogalakustik.com/depo/sayfaresim/file/woturoripelax.pdfIn PDF document text
    • http://russkiivopros.com/images/FCKeditor/file/tuxarax.pdfIn PDF document text
    • http://vibrobeton.by/pics/files/8396795047.pdfIn PDF document text
    • https://thepainter.asia/upload/files/42618212373.pdfIn PDF document text
    • https://www.truck-transport.com/ckfinder/userfiles/files/56202850186.pdfIn PDF document text
    • http://hondatayho.vn/images/ckeditor/files/bijomumerubuziwejora.pdfIn PDF document text
    • https://www.peltonfell.org.uk/ckfinder/userfiles/files/82406558131.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16136aab0f376c---nawegupefafurebabubogeve.pdfIn PDF document text
    • http://asremajazi.com/uploads/files/41975163706.pdfIn PDF document text
    • http://nova-auto.com/upload/wikebozajulo.pdfIn PDF document text
    • https://corianderedmonton.com/ckfinder/userfiles/files/fuzadorup.pdfIn PDF document text
    • http://noithatsah.com/webroot/img/files/sigad.pdfIn PDF document text
    • http://smalternatywa.pl/media/upload/files/d474d6c50a084c0996a75879c5b50753.pdfIn PDF document text
    • http://studiotrusso.it/userfiles/files/95121477097.pdfIn PDF document text
    • https://gmt-tw.com/app/webroot/userfiles/files/gagupeselifeguvilow.pdfIn PDF document text
    • http://zhfangyuan.com/uploadfiles/files/91476208325.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=best+free+icon+packs+androidPDF 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_off0000f136.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF136 19464 bytes
SHA-256: d53942d7246c37cedafe8c00b14e755cb6c211248f150373c44082dd8d783d47
font_01_sfnt_off000123c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013bdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BDC 10712 bytes
SHA-256: 3f37af122ec47d6a4a66e1cad9b4e87ee9804898fb021a0ebd6efcb15d2f90b9