Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8a50a396526e5d5…

MALICIOUS

PDF

80.2 KB Created: 2021-10-09 21:13:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 8ff3b6369ff2d57f8ca5ab0841cb7bb8 SHA-1: 1218d66504518c3105fa81e4873e291f299e5adf SHA-256: c8a50a396526e5d5a8de8d0a79cc89fde1bb1a0e6998882d8cea38e638a9c13a
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to external PDFs hosted on various websites, indicating a link farm or redirection mechanism. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure points to an attempt to redirect users to malicious content.

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://ambulatorioveterinariorigolon.eu/userfiles/files/penipiw.pdf In PDF document text
    • http://kxqcgs.com/filespath/files/20211003044924.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2886bb199---babazowoguto.pdfIn PDF document text
    • http://aimecostruzioni.it/userfiles/files/65838888189.pdfIn PDF document text
    • https://jackinthegym.com/uploads/files/202109060650253430.pdfIn PDF document text
    • https://casasholidays.com/scgtest/team-explore/uploads/files/zojoxefetetobep.pdfIn PDF document text
    • http://tramtronbetong.com/uploads/userfiles/file/71227258505.pdfIn PDF document text
    • http://mbeautyconcept.com/upload/content_images/file/ranitetalev.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138eb51389a1---81917042933.pdfIn PDF document text
    • https://asiastudy.in/ckfinder/userfiles/files/49923845893.pdfIn PDF document text
    • https://bibonatura.com/ckfinder/userfiles/files/4814328910.pdfIn PDF document text
    • http://totoquynhhuong.com/upload/files/1293503315.pdfIn PDF document text
    • http://coachhouse.info/assets/file/bifajiv.pdfIn PDF document text
    • http://ipceurope.be/assets/file/dudilotozegeropus.pdfIn PDF document text
    • http://www.smpnuenen.nl/images/files/sizelinotowunigala.pdfIn PDF document text
    • http://cauthangdep24h.com/upload/files/52794367900.pdfIn PDF document text
    • http://nanumed.ro/uploads/files/26625760228.pdfIn PDF document text
    • https://tranthachcaodanang.thicongmaiche.com/uploads/image/files/75761363930.pdfIn PDF document text
    • https://chambres-lannion.fr/userfiles/file/47026099919.pdfIn PDF document text
    • http://reklama-kemerovo.ru/files/files/jerugajaf.pdfIn PDF document text
    • http://personal.sut.ac.th/chantira/port/ckfinder/userfiles/files/jenuwawepirerunama.pdfIn PDF document text
    • http://studiotecnicodambra.eu/userfiles/files/39846007752.pdfIn PDF document text
    • http://hebakotb.net/userfiles/file/18729703633.pdfIn PDF document text
    • https://shioturboapi4-xyz.com/contents/files/xabeka.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=hd+lace+meaningPDF 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_off0000d5e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5E2 10220 bytes
SHA-256: 4f8c8388397bd1bb9ea9726baa2489c3dda0995b9fd5b5727039bad79c3f79b0
font_01_sfnt_off0000ec6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC6E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010480.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10480 18228 bytes
SHA-256: 8abfa9c0a0f0c5765088d7c8b1471d535ea439535c0d39117c2c4b1ba029857c