Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7789f450c8b9b40…

MALICIOUS

PDF

81.3 KB Created: 2021-10-07 06:08:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b9c91397498e6f99b08f13151e48d9ea SHA-1: b830ee6d5717c8435d42361abd113d8f51949d67 SHA-256: b7789f450c8b9b40fa14e02ee0d04cdef7ccbae6f50042cba63a4bba04ea938f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The document contains numerous embedded URLs, many of which point to disposable hosts and appear to be part of a link farm, suggesting an SEO poisoning or content distribution scheme. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://wills-machine.com/UploadFile/file/sofuposirex.pdf In PDF document text
    • http://bigbulkbags.ahmadpackages.com/survey/userfiles/files/17826842775.pdfIn PDF document text
    • https://divinenine.net/userfiles/file/tixatanumezabuvibada.pdfIn PDF document text
    • http://interreg-ipa-husrb.com/downloads/tofexaremi.pdfIn PDF document text
    • http://brukikostka.pl/uploads/page/file/65962612350.pdfIn PDF document text
    • http://naoshima-habitant.com/images/blog/file/bakifilememu.pdfIn PDF document text
    • https://resttour.com/images/userfiles/files/21741838250.pdfIn PDF document text
    • http://citty.org/images/uploads/file/99282256615.pdfIn PDF document text
    • https://exam11.menapoint.com/app/webroot/upload/files/16941941704.pdfIn PDF document text
    • https://denizlihorozu.com/resimler/files/todefoxemedotuxijesimo.pdfIn PDF document text
    • http://dges.in/userfiles/file/logifupudufasotemolag.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161377c048dc77---12159476000.pdfIn PDF document text
    • https://dottoridegregorio.it/public/file/31314905681.pdfIn PDF document text
    • http://broadgatecapital.com/userfiles/file/babuwosusitezazavij.pdfIn PDF document text
    • http://cokhilegia.com/upload/files/dorakutanevetubebejakimu.pdfIn PDF document text
    • http://yuli-china.ru/d/files/ludodu.pdfIn PDF document text
    • http://www.medic-pneumolog.ro/fisiere/file/farisut.pdfIn PDF document text
    • https://lazeo.nl/userfiles/file/sudofupudime.pdfIn PDF document text
    • http://staractivecollection.com/resimler/site/files/60464689971.pdfIn PDF document text
    • http://apsara.ru/userfiles/file/geviruzedilireda.pdfIn PDF document text
    • https://perfecthospitals.com/ckfinder/userfiles/files/muvoxanotosilivagewuboxir.pdfIn PDF document text
    • https://jewfri.kr/files/image/files/57584872106.pdfIn PDF document text
    • http://cuathepvangohaiduong.com/images/ckeditor/files/34222836416.pdfIn PDF document text
    • http://wiskind.com/filespath/files/20211005050422.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161542ca313f44---53345130672.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=partition+table+loopPDF 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_off0000d597.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD597 10216 bytes
SHA-256: f683e84e252de3c8cfdf8f60a82339c243d29dc8491e60b01416f049b83a3dd8
font_01_sfnt_off0000ec58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC58 19384 bytes
SHA-256: d2aa5b287628e8bb383a1881e3d885cba66d35f3c45e5ffe6e2a74457189b834
font_02_sfnt_off00011f4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F4D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1