Malicious PDF — malware analysis report

Static analysis result for SHA-256 c87ae6c6494e751f…

MALICIOUS

PDF

88.0 KB Created: 2021-08-20 17:11:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1db916e4d0d04a1b88f1c19e98e90ae6 SHA-1: 3f89c394b523acf0500a08b571e85c32b73c4b64 SHA-256: c87ae6c6494e751f14b242da0596177cca8cde94a2aa9f6ad640918ad50a6191
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm, with many distinct hosts and links pointing to potentially compromised CMS upload storage. The ML classifier and ClamAV also strongly indicated maliciousness. The document's structure and embedded URLs suggest an attempt to redirect users to malicious sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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 http://sladkiy-ostrov.ru/userfiles/files/dotixajuz.pdf In PDF document text
    • https://cabsfromheathrow.com/userfiles/file/tojuzuza.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/4db69f7235c5f7718bdbcc47cb2dd82a/majezapujutojo.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/9ushi76et3m2oanq0q22a9ffq2/bufanebafidirewu.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/8a41co0n34dt79ick5vvc8qcl7/17281971482.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/a5fe4nfs91bg36vhnbhcjhn3ui/54053673041.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8cb51d1409---98110042424.pdfIn PDF document text
    • http://bbpcosmetics.com/admin/upFiles/2021-7/file/kawofisumujepul.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/160c93ecca8630---46452723526.pdfIn PDF document text
    • http://eros-arena-reutlingen.de/eros/userfiles/file/zepifatutupivewosulone.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607a30541a458---12191723580.pdfIn PDF document text
    • http://jun-travel.com/userfiles/file/gebomi.pdfIn PDF document text
    • http://gramercy-grand.ru/files/file/23724963422.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/63205011922.pdfIn PDF document text
    • http://crystalsteakandstogie.com/clients/1/1d/1dbb6d5698303b6304ae84622e226a19/File/pevobiladol.pdfIn PDF document text
    • http://longarmacademy.net/fckeditor/userfiles/file/sofebazawadomoxok.pdfIn PDF document text
    • http://donahoelawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/6424375763.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/77858672236.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ee24cd31f0e---65339210529.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/1gf5jbu7au866e8v8e0ud004a7/joguditebufoxi.pdfIn PDF document text
    • https://canevastoilestjean.com/upload/editor/file/denamibutowetevitikefoju.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1611d76aa7615d---71615695125.pdfIn PDF document text
    • https://agrimal.pl/userfiles/file/91077684414.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/81871291039.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=issa+workbook+and+study+guide+answersPDF 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_off0000efe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE0 18628 bytes
SHA-256: 2e57164cc85b8066d382666c36a36374cf1fb9ae6c9c1943b34a65d000ff9733
font_01_sfnt_off0001200a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1200A 10860 bytes
SHA-256: 9e5e9024df225c4de371e569760bce5dc5409e64a6fb1091755ce6dd81548d98
font_02_sfnt_off0001392a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1392A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1