Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f7a5da21039c7f4…

MALICIOUS

PDF

81.5 KB Created: 2021-09-01 13:31:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 22fddda8cc532294b92ed34d87e93c21 SHA-1: 9783b733de10de7826d6271b70a9619a49c7c20f SHA-256: 6f7a5da21039c7f495d47bc56edaf71b231dc8e6a0b0a4f9d587a7faa5f0f395
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting it's designed to redirect users to malicious content. The ML classifier strongly indicated maliciousness, and the heuristics identify it as a link farm on disposable hosting. The document body is heavily obfuscated and unreadable, providing no further context on the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • 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://coretry.ru/uplcv?utm_term=a+psalm+of+praise+to+god PDF link annotation
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fdf5eb9782c---sasexelekaxenuxerevagedel.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/99f29088dcb1c89ae8a6c5da46b6609f/rulini.pdfIn PDF document text
    • https://clubelsendero.com/img_pag/file/33705064476.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cdc1285133---97871126194.pdfIn PDF document text
    • https://www.elitelawnsolutions.co.uk/wp-content/plugins/super-forms/uploads/php/files/9r0stg1g5s21jn70f70ul3oip5/61896724373.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba93df15d9b---bakujamejegobemebinuzovij.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a721f1128d---66240642655.pdfIn PDF document text
    • http://scro.ru/pic/file/vosasenusosalati.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/17272473869.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ddc41190b6f---68171364382.pdfIn PDF document text
    • https://ketdoanbus.com/webroot/img/files/wafiruvobuxiwuvi.pdfIn PDF document text
    • https://rosewoodcity.org/nbloom/fckuploads/file/jevamuravuteta.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/86b315fe86457a69fa74bed22018e77a/fuwoxi.pdfIn PDF document text
    • http://nbpcpentecostalchurch.com/clients/65183/File/70553120535.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/771212628add82685d65fe4bd1224044/fezutitipoziwov.pdfIn PDF document text
    • https://www.alphaveneers.com/wp-content/plugins/super-forms/uploads/php/files/21853c2196c9c60074099fe24349e698/65113690969.pdfIn PDF document text
    • https://standsimulator.com/ckfinder/userfiles/files/zinumiketab.pdfIn PDF document text
    • http://mptech.vn/ckfinder/userfiles/files/72556687332.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160870f3b2c89e---sudodederer.pdfIn PDF document text
    • http://10glazsikeyrosa.ru/file/39984674646.pdfIn PDF document text
    • http://burbank.kopanramen.com/uploads/files/remejikelutixa.pdfIn PDF document text
    • http://ilovechardonnayhills.com/userimages/wejeta.pdfIn PDF document text
    • https://aful.edu.pe/ckfinder/userfiles/files/bexuxobexaduxirubukawuz.pdfIn PDF document text
    • 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_off0000db98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AA 17212 bytes
SHA-256: 6406f81a873b793b547cc356af31918f49c8ebf810f9b58ad8bef4e007c322ff
font_02_sfnt_off00012047.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12047 10720 bytes
SHA-256: 8fd59094e9a22dc0fe7dc0807248bbeba1d5594c3dccf7f5d226814112b7e272