Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5f7be0542a4c798…

MALICIOUS

PDF

80.9 KB Created: 2021-06-25 14:42:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9d898558ca36ede3398e383dcd0b9f9b SHA-1: c2d615a084400ce797155f23a8923f3e4176165d SHA-256: c5f7be0542a4c79855c3d969bf972701d04f8b7fae5b1ecef9426c2d576f8fa6
156 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, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised WordPress uploads and other potentially malicious sites. The document body is unreadable, but the heuristic firings strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://schlosshotel-murten.ch/userfiles/files/nabunarenik.pdf
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/7dc25fe704d586fb1ed7b95cbca134bf/sakarajofon.pdf
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d5038e100d2---13316491376.pdf
    • http://schooldistrictservices.com/clients/f/f6/f6ab1571d2cdf5e569af7b76e288b17c/File/goxesapofi.pdf
    • http://ahxxzx.com/userfiles/202105/file/60379774089.pdf
    • http://sakaryakasaplarodasi.org/userfiles/file/wisuwurugonuniwixek.pdf
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/b25f0efdfc3a37ac5170353a2f699663/xiloxezonifabesorinami.pdf
    • http://apisicul.com/userfiles/files/96840238081.pdf
    • https://celebicatering.com/upload/ckfinder/files/83902344024.pdf
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607d6f8e9b3e6---71256968231.pdf
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e242abb141---81362460530.pdf
    • https://honda-otolongan.com/upload/files/88080925425.pdf
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/2680acacb603323a20c8cf7310ad48ed/3088576564.pdf
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b741a58695a---zakepufoxevivakofusis.pdf
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/n528ohg0c47pm5vv6ffv2nmouu/50089953649.pdf
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083a60d952b9---fuxabatemakizorebopun.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=why+is+yeast+alive
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd4d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD4D 16792 bytes
font_01_sfnt_off0000f564.bin
fa6c32c993004710776fdc7c852ee150a7afbb650ec233153926116893bab571
pdf-font-stream PDF embedded font (sfnt) at offset 0xF564 10056 bytes
font_02_sfnt_off00010be9.bin
adaa9dfb8501fd9db0e9eb6fd8917e4bfbc857b1dc0d310c25d52541c6897a1f
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BE9 16672 bytes