Malicious PDF — malware analysis report

Static analysis result for SHA-256 170c255fb3f6a97b…

MALICIOUS

PDF

67.7 KB Created: 2021-10-08 17:50:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: da7d87279d2b4d0f80bbf51e52515606 SHA-1: 82daca3ce5320c24be5259c016e5ed4d453ceea8 SHA-256: 170c255fb3f6a97b80348ebc3d9930dc0fab9dfa789498a62cb7624efe68656a
166 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV and an ML classifier. Heuristics indicate it is a malformed exploit stream and an image-only document designed as a phishing lure, containing numerous links to external PDF files. The document body is heavily obfuscated, preventing a clear understanding of its specific intent beyond being a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 67 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://corse.annuaire-regional.com/ckfinder/userfiles/files/kogowewuzuboduzadunu.pdf In PDF document text
    • https://eseninternational.com/uploads/files/vaponigawa.pdfIn PDF document text
    • http://skulpt.in/admin/uploads/file/jubaboxataposikepigezifug.pdfIn PDF document text
    • http://iuf.kr/pds_down/files/66066682011.pdfIn PDF document text
    • http://obrienbuilders.com/userfiles/file/47245199287.pdfIn PDF document text
    • https://nobelboya.com/userfiles/file/fodugolinavubigoxizamuju.pdfIn PDF document text
    • http://podolsk-kondicionery.ru/upload_picture/file/24798547945.pdfIn PDF document text
    • http://hospitalitan.com/sites/default/files/file/66618672786.pdfIn PDF document text
    • http://hotelrefah4ter.ir/basefile/hotelrefah4terir/files/74508034813.pdfIn PDF document text
    • https://bluetact.com/ckfinder/userfiles/files/vedowoxijow.pdfIn PDF document text
    • http://yogaschoolofkerala.com/photos/editor/files/20588264880.pdfIn PDF document text
    • http://elrey-uslugi.ru/media/file/87342861111.pdfIn PDF document text
    • http://sspvjd.com/FileData/ckfinder/files/20210914_45D6B07342D390FB.pdfIn PDF document text
    • http://7m-shop.com/userfiles/file/74626301890.pdfIn PDF document text
    • http://daiichihr.com/uploads/news_file/gobebozufakipigibonodib.pdfIn PDF document text
    • http://www.ctnphrae.com/ckfinder/userfiles/files/gidigepajunizewiro.pdfIn PDF document text
    • http://lsphc.com/userfiles/file///jekewakotojoluz.pdfIn PDF document text
    • https://haruhonpo.com/upload/haruhonpo/files/gatezafagepenifikebesa.pdfIn PDF document text
    • http://italy-ex.com/images/blog/file/satovukovenu.pdfIn PDF document text
    • https://ajur.rest/uploads/userfiles/file/vuwopi.pdfIn PDF document text
    • https://ehbo-oostkapelle.nl/userfiles/file/25191008515.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/dc44e273b9b0fb0feb42d52f9b25dd47/luvojakur.pdfIn PDF document text
    • http://namuvaldymas.lt/userfiles/file/12259606915.pdfIn PDF document text
    • http://thepnguyentran.vn/media/ftp/file/7007046259.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=tasks+and+subtasks+in+projectPDF 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_off0000ae3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE3C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c653.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC653 10888 bytes
SHA-256: 081e64cff9e63c1d08b28e1fb48653650db3e203b33681bf86a1bec290753848
font_02_sfnt_off0000df6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF6A 13940 bytes
SHA-256: ee7a66070e834d0e9194f62cc7c60f294681ba8176cacb448aa648d09ad3ed18