Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b3feb0a6906da11…

MALICIOUS

PDF

82.9 KB Created: 2021-09-09 04:16:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1cdf0435ce53cec0a611a069866a31fd SHA-1: ff5c131c18605db4fbb499339a2888e80d5d7c64 SHA-256: 4b3feb0a6906da114f9d6d22a6255c9986fd7e937ee760aaac4d2eead3b9041f
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to disposable domains, suggesting it functions as a link farm. One notable URL, http://nikacarpet.nikacarpet.com/My_Project/Hamishe_bahar/ahar_img/files/2546335405.pdf, is part of this farm. The presence of external URIs and the link farm structure strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nikacarpet.nikacarpet.com/My_Project/Hamishe_bahar/ahar_img/files/2546335405.pdf In PDF document text
    • http://banglatalkies.com/dynamic-images/cms/file/9072025502.pdfIn PDF document text
    • http://vervesimuhub.com/userfiles/file/80355757487.pdfIn PDF document text
    • http://christmaslandint.com/userfiles/92403017291.pdfIn PDF document text
    • http://orgue-chantepie.info/FCKeditor/upload/file/42337400452.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/ivuxigemuluzujemuripis.pdfIn PDF document text
    • http://yilip.net/userData/board/file/fegefesodupikigowikevexo.pdfIn PDF document text
    • http://net-work.cz/data/file/miwemepudediwisetaruzu.pdfIn PDF document text
    • https://rugerwafers.com/demo/ruger/beta/userfiles/files/tejexerufike.pdfIn PDF document text
    • http://romento.com/uploaded_files/userfiles/files/14478564301.pdfIn PDF document text
    • https://ristovski.mk/public_html/upload/userfiles/file/jezigojarizoluxalijadi.pdfIn PDF document text
    • https://anukulagrotech.com/ci/userfiles/files/kajiwiputofelameko.pdfIn PDF document text
    • http://seksdagen.nl/userfiles/file/zijere.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395e5321550---38516687460.pdfIn PDF document text
    • https://stomatoloska-ordinacija-rijeka.com/files/ragetepose.pdfIn PDF document text
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/11499916402.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/lubugu.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/xazuk.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/vovonulopekijol.pdfIn PDF document text
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/98122447607.pdfIn PDF document text
    • http://flapboxes.com/userfiles/files/94454033291.pdfIn PDF document text
    • http://thuduchouse.vn/pics/file/zugokezapegogewajikisuma.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=b612+app+old+versionPDF 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_off0000db5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB5B 10744 bytes
SHA-256: 64135e9b300bddf4c558b5f8b6b10ab865291329842e50d829edfd298b68d70d
font_01_sfnt_off0000f448.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF448 18884 bytes
SHA-256: caf94a82433612b7344d2d1385267978b85ae099ddae048762cb713dc5248966
font_02_sfnt_off000125c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1