Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5c8491572c8a1d0…

MALICIOUS

PDF

73.2 KB Created: 2021-09-29 12:41:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3efbb2e763505cca18c46dddf49d3bd8 SHA-1: 670544c7c89c9a9fd609aab0909933c4c24c554a SHA-256: c5c8491572c8a1d07ed7844a65fb6a9d3327d59d9f484ef95c2faf68d2bc37f2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs pointing to various domains, many of which are associated with compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly supports the attack pattern of using a document to host a collection of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://wastran.ru/uplcv?utm_term=open+sea+map+android+download
    • https://yellowstonewildlife.com/vakop.pdf
    • http://automyjka.pl/automyjka.pl/userfiles/file/muxesexotanelix.pdf
    • http://savemaxint.com/files/file/8411553443.pdf
    • http://joyearland.com/ckfinder/userfiles/files/xifiwunos.pdf
    • http://wannawwannie.pl/userfiles/file/bikagujuzet.pdf
    • https://asiastudy.in/ckfinder/userfiles/files/loxavotususekuwib.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16142415b19bc0---kigavoporawaxenilul.pdf
    • https://freshchannels.com/home/sites/freshchannels/public_html/ckfinder/userfiles/files/30234363381.pdf
    • https://mbamantra.com/ci/userfiles/files/34049044380.pdf
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16149b4e0457a9---bopazi.pdf
    • http://hometextiles-consultant.com/ckfinder/userfiles/files/lovafavimirepibekafaguta.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6642dcc79bd3b12cacf49be10d83a0ef/vikuva.pdf
    • http://markasib.ru/ckfinder/userfiles/files/govarebudulukikuzufo.pdf
    • http://sipzip.com/userfiles/file/wasawu.pdf
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614dd6f2e8332---30756969404.pdf
    • https://saglamahsapkutu.com/img/editor/image/file/71614408990.pdf
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16134bcc1c4e38---mutokutamujimawal.pdf
    • https://mjrspot.com/fckimages/file/41002525754.pdf
    • https://cauthinh.com/luutru/files/80087381910.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16131bc3f0dfa4---99549841547.pdf
    • http://sswjeans.com/files/bitijifimajamepodesaxi.pdf
    • http://auto4-spb.ru/public/images/ckfinder/files/wikixamejigejawe.pdf
    • https://lufty.cz/UserFiles/files/barosoti.pdf
    • http://stillincontact.com/images/mails/file/14209415714.pdf
    • http://akkoryazilim.com/userfiles/file/vinowejono.pdf
    • https://landatur.com/files/galeria/files/67469757244.pdf
    • http://www.plan.msu.ac.th/ckfinder/userfiles/files/2989766468.pdf
    • 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_off0000b6b9.bin
0381fe41fc89ca0bbb15d0ccfcf228b3e62f8e7efb1338573b21fd91f464beb6
pdf-font-stream PDF embedded font (sfnt) at offset 0xB6B9 18264 bytes
font_01_sfnt_off0000e53a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE53A 16792 bytes
font_02_sfnt_off0000fd51.bin
f3ca15760146109c2459c4a6b614ea5e5cb826b548cb87d0596e4ca815bab225
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD51 10564 bytes