Malicious PDF — malware analysis report

Static analysis result for SHA-256 100660622a0f726f…

MALICIOUS

PDF

84.1 KB Created: 2021-08-21 23:33:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 48d786891f070f27032fe7f2d8ded029 SHA-1: e70dbb92dd7c09585f61a5a885d9f1be1fd6ee6e SHA-256: 100660622a0f726fcce49f0a293c4584cb9a8e44dde8c4e429cd80bb862ff9de
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier with high confidence. It contains numerous links pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/16071234278afe---83546730454.pdf In PDF document text
    • https://uat-tunisia.com/userfiles/file/95957130291.pdfIn PDF document text
    • http://www.bluefashion.cz/ckfinder/userfiles/files/sedalikijonavepem.pdfIn PDF document text
    • http://geyikkimya.com/userfiles/upload/file/dejakilituvotoxabujotone.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077b657de3a1---ronojopom.pdfIn PDF document text
    • http://affordableadobe.com/ckfinder/userfiles/files/41486371571.pdfIn PDF document text
    • http://iiiemjobs.com/FCK_Editor_Images/files/38600699456.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160944b69bda5a---suloniguravagorusumomit.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1609c8b91ecb0d---garujemu.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b4363675a25---94516917765.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/53468199695.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/396f3a0f107f70d90bf03767f685ad0a/63129032494.pdfIn PDF document text
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077f2187a1b7---98756221314.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/e3326adb8c726bf1578661b954c3da09/20215483916.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b440732bc03---zugulij.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/n33dokrnig0f6om83nllmnj8f6/lakefuni.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-5-14/20210514081349556942.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160bc2a81d8054---lixorej.pdfIn PDF document text
    • http://glina-master.ru/admin/ckfinder/userfiles/files/gadesizemiza.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/glra2kvo9vthjjpjsg0dod8vo2/1791300967.pdfIn PDF document text
    • http://xingyeknitting.com/userfiles/files/gasivopowix.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16087ffdb1361c---84553996320.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=what+to+do+if+your+iphone+7+will+not+turn+onPDF 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://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_off0000e5da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5DA 10768 bytes
SHA-256: ae3dd897096727a69500dc29bda0ad13f12e577a979af9a39633802ab06ea2e9
font_01_sfnt_off0000fea9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEA9 17844 bytes
SHA-256: 2244a7442cf10569ea7f34ba65e5f6ee642619974d420bec247c1bf0e4f24b48
font_02_sfnt_off00012c73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C73 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1