Malicious PDF — malware analysis report

Static analysis result for SHA-256 51a9b8b10783d0b9…

MALICIOUS

PDF

95.2 KB Created: 2021-09-01 13:19:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5e78033c9655ed26a324e429c48f290f SHA-1: 504d96ae2bdfba030b5bc51c52b14047e9df0390 SHA-256: 51a9b8b10783d0b92476b053f624f00f8f839543dace1c4eaf4bc4aa9c32e6a2
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to potentially compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious files. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to host and link to further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 http://goldendoodlesofthesierranevadas.com/userfiles/file/vekedurufavivosorijadab.pdf
    • https://elitstroycraft.ru/source/file/jaxeresij.pdf
    • http://lex-ter.ru/admin/ckfinder/userfiles/files/49750319951.pdf
    • https://cosmeticdermatologymiamibeach.com/uploads/data/files/xabipepinitoxevovexolo.pdf
    • https://emenu.hu/editor_up/forizo.pdf
    • https://childprotectionindia.com/lexcyberia/userfiles/files/doxatevamofawaneno.pdf
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160d2ff6e58524---77532291225.pdf
    • https://thinkglobalcompliance.com/ckfinder/userfiles/files/matuzeva.pdf
    • http://womensmentalhealthmd.com/clients/9/9a/9a9ccad1be43d50cbc9928f06550b956/File/fonilevalububadeletevidu.pdf
    • http://kondicionery-elektrostal.ru/upload_picture/file/85245206365.pdf
    • http://elskenecologie.nl/files/82613326685.pdf
    • https://bhsbeacon.com/FCKeditor/file/26435204357.pdf
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/e55u4ngh8pgtaaofo0a8obuui6/vajoxudumimajisemajiwoze.pdf
    • https://associazionedynamica.it/uploads/file/27113028289.pdf
    • http://miltonhigh65.com/clients/874455/File/32030770374.pdf
    • https://sunrise-photon.com/upfiles/editor/files/finulatata.pdf
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/6147e358397e3f1ca2b8ec17eb704334/84674824646.pdf
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/17247701dc8ccce79e48c2f8e367f78a/22345492758.pdf
    • http://hodori247.com/uploads/files/desupoxafokogobiva.pdf
    • http://rauvuonsach.com/images/uploads/files/34728856132.pdf
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/3ef1691499b8c4e77c85751247a6266b/37019050659.pdf
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098662f9002b---21159492478.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=introduction+to+responsive+web+design
    • 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_off00010a1b.bin
43d5f533a97671c5a5a55334f9e2323f65c2708fe61542071eeff89cd6e61f1b
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A1B 10824 bytes
font_01_sfnt_off000122d5.bin
f0bc8d09f51bf03030d56c1dcb0f28110d841a249c7b9671a4db6414f726fc6b
pdf-font-stream PDF embedded font (sfnt) at offset 0x122D5 19360 bytes
font_02_sfnt_off0001561b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1561B 16792 bytes