Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0a6736696fe5866…

MALICIOUS

PDF

74.5 KB Created: 2021-09-04 03:20:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 4265760e51ffb100bd401d853a244426 SHA-1: fe8438130e11f94eabd78f08d8ac4c23c88bab29 SHA-256: a0a6736696fe58668615222ee92fb042595e121e594a46dd06b208826da0504f
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of external links, many of which point to compromised websites or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the nature of the link farm suggests it is likely used to distribute further malicious content or for SEO manipulation, potentially involving embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://inwebjor.ru/uplcv?utm_term=psychophysiological+disorders+pdf PDF link annotation
    • http://uci.ir/userfiles/file/fetomasodijeji.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160bab88e5baec---82593321304.pdfIn PDF document text
    • http://sictombbi.fr/ckfinder/userfiles/files/biturunokozulitawugenujur.pdfIn PDF document text
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/bb4ad34f8e0a078f7611faa4a730efb4/94856697741.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/9be771e2c1383e4a274d7de9167f99c6/gorofazuduzofutav.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/811a41b11b6d973e7ce53642d3bebcfa/xosilunamafi.pdfIn PDF document text
    • https://oncallanatomist.org/ckfinder/userfiles/files/36855901873.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/2a4e05dff458f7ef5d6fdbb45bf6007f/dajogemimaluxeg.pdfIn PDF document text
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/fcfb716b3c97adc1947950626678ab20/robevirameluziwekimisefi.pdfIn PDF document text
    • https://www.marvistasales.com/wp-content/plugins/super-forms/uploads/php/files/9dc604ad7a6ee5a5bd77459d008f4a00/47850102088.pdfIn PDF document text
    • http://jsdarvin.com/files/90943010846.pdfIn PDF document text
    • http://amctop.com/board_data/editor_img/file/202105290808.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7f09b805c1---gisowulijoripekedesule.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/58683605052.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608edf65b0150---70350459270.pdfIn PDF document text
    • https://sonarmusic.hu/up_image/file/gizosejexefivukadex.pdfIn PDF document text
    • http://centrumbiznesurawicz.pl/userfiles/file/pedomijiwovafakuzujex.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607a10646af1b---53341679658.pdfIn PDF document text
    • http://jaluzipro.ru/public/userfiles/file/49914820332.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/t9t0innsapbrmho351gagfaelh/66608412944.pdfIn PDF document text
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a88e2beb451---42163006274.pdfIn PDF document text
    • http://reylab.com/userfiles/file/47557239763.pdfIn PDF document text
    • http://hondatayho.top/img-ngocbao/files/68210596941.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/07e337835460ef93d973b05a06614539/87246265264.pdfIn PDF document text
    • https://icon-studios.com/userfiles/file/67638632419.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_off0000c0be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0BE 10812 bytes
SHA-256: 241b5fccff92cbfdb03e649f146b6e93282317204d50960a1f8cb42810ebf311
font_01_sfnt_off0000d9a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f1b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B4 16680 bytes
SHA-256: fb25d1e0e1a229a47e003220a067a65f0b16b4425577144315aeb1bccad835e8