Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b09899e76c14980…

MALICIOUS

PDF

80.6 KB Created: 2021-09-06 01:08:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 56f38b01fa4e0bf9b4557169d4fe1a8d SHA-1: 8fd1276cc7e493fb8475d7124de015d417418099 SHA-256: 2b09899e76c149802f34107e46329af52c7f46d4076f62e57e946f4826245ea0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, many hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious sites. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this. No scripts were extracted, but the overall structure points to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 https://philabc.ru/uplcv?utm_term=insertar+archivo+pdf+en+word+como+icono PDF link annotation
    • https://arch.ua/ckfinder/userfiles/files/bunusavokakuvezebuto.pdfIn PDF document text
    • https://trouver-une-ssii.com/img/pics/files/sivabilog.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609611f9b5ce5---87731088374.pdfIn PDF document text
    • http://cgl.lu/userfiles/files/zamubuvoxugudabemis.pdfIn PDF document text
    • http://www.bluewhaleline.com/image/upload/File/55264552836.pdfIn PDF document text
    • https://catbasailing.com/upload/fck/file/91967104196.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c29bf1db960---vidoxowifikexetunarim.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16080948eb4c58---senosem.pdfIn PDF document text
    • http://bishnutoursandtravels.in/userfiles/file/kupupukamipobubexalitug.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085ba8d902c2---78803390680.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/05382bba79c95a5e89030ec24384e589/gotag.pdfIn PDF document text
    • https://jahanchart.ir/data/files/file/mojojax.pdfIn PDF document text
    • http://cokhihoangvinh.com/uploads/userfiles/file/buxoga.pdfIn PDF document text
    • http://ned.ru/uploads/files/4922349732.pdfIn PDF document text
    • http://gps-ambroisie.com/ressource/site-image/files/gebisigo.pdfIn PDF document text
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/6217da1abe0c949b1cbd4f29b7ca6edc/silesimokufa.pdfIn PDF document text
    • http://ivepe-elearning.gr/assets/UserFiles/mainHome/file/80469790979.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c2526e714b8---kedozegexetewilafem.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_off0000d538.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD538 17768 bytes
SHA-256: 9b4e27c99a45e1ae37757bae04b257e98b9b8770c627731bf6e7e07dbbb498c6
font_01_sfnt_off0001038f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1038F 10940 bytes
SHA-256: 861e03b0b732008faf008e32dc0fb6030c4c5da677107222e1a8f7476961963a
font_02_sfnt_off00011cce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CCE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1