Malicious PDF — malware analysis report

Static analysis result for SHA-256 681a4768a7bae34b…

MALICIOUS

PDF

72.4 KB Created: 2021-09-28 00:05:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e71508e891e797a32114c49fa31daceb SHA-1: 5192eccd336fdfae5004bf7cfbb4de3218285a6c SHA-256: 681a4768a7bae34b37fa85e6fabbc0bef31b8a0d7bb10994891e054bb23e7352
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs and is identified as a link farm, suggesting it's designed to redirect users to potentially harmful websites. The presence of embedded URLs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic further support this conclusion, pointing towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

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://huntic.ru/uplcv?utm_term=how+to+switch+over+contacts+from+one+phone+to+another PDF link annotation
    • http://nt-module.ru/ckfinder/userfiles/files/90273351912.pdfIn PDF document text
    • http://villaelen.it/userfiles/files/72362096193.pdfIn PDF document text
    • http://baldonimarcostudio.eu/userfiles/files/vozerugorab.pdfIn PDF document text
    • https://pharma-tools.eu/galeria/file/lerepino.pdfIn PDF document text
    • https://fentesmakina.com/paket/upload/files/51425784153.pdfIn PDF document text
    • http://104408017.linker.tw/files/80654733369.pdfIn PDF document text
    • https://lekkermooi.nl/userfiles/file/jivexasinovulepezus.pdfIn PDF document text
    • https://mygenius.ru/admin/ckfinder/userfiles/files/mideduve.pdfIn PDF document text
    • http://weddingdove.tw/uploads/files/202109141647401907.pdfIn PDF document text
    • https://dmshospital.com/mm_engg/files/funodamudesedovesigosuweb.pdfIn PDF document text
    • https://vsetinrally.cz/userfiles/file/pulijuzamenijidipik.pdfIn PDF document text
    • http://computergramm.com/userfiles/file/80803173526.pdfIn PDF document text
    • http://demo755.webbazaar.com/uploads/gufadike.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff84d87e0c---36640674748.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/59251775949.pdfIn PDF document text
    • https://klcmekatronik.com/ckfinder/userfiles/files/53956208424.pdfIn PDF document text
    • http://yavuzselimvakfi.org/resimler/site/files/92311456370.pdfIn PDF document text
    • http://studiogallerani.it/userfiles/files/10325704910.pdfIn PDF document text
    • http://machin.kr/userData/board/file/981394107.pdfIn PDF document text
    • http://boldino-hotel.com/ckfinder/userfiles/files/lebot.pdfIn PDF document text
    • http://chieucoingason.vn/files/teziwumukode.pdfIn PDF document text
    • http://aotwresort.info/ckfinder/userfiles/files/wobekufo.pdfIn PDF document text
    • http://rancholasmonturaspremios.com/campannas/file/wasawojapedewogo.pdfIn PDF document text
    • https://theloneranger.tv/clients/loneranger/ckfinder/userfiles/files/bepuvexosazexidig.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16136fffc677c2---ligik.pdfIn PDF document text
    • http://2sisaccount.com/userfiles/files/18196133906.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_off0000b762.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB762 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF74 16840 bytes
SHA-256: d6a9e5c96ace823a602cb84c119ce90d1e4dd881a7dc2f660384a677b748566f
font_02_sfnt_off0000fa47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA47 10844 bytes
SHA-256: e613364b4f164dfc862faf42e80980de679701edb63a1a61cefa81b793335c23