Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cda4b45dc50d86c…

MALICIOUS

PDF

83.4 KB Created: 2021-07-06 16:36:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3fdc295bc11fed85ae53a000a2a0fa42 SHA-1: 81caef20c16b1a7674ac2b80fca164a73dae4d96 SHA-256: 1cda4b45dc50d86c6e4e1b88d9c29f7eab0bf981158ad0a7ff7899bccc24715f
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to potentially compromised WordPress upload directories or disposable hosting. The document body is heavily obfuscated, preventing analysis of its specific content, but the presence of numerous external links suggests a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://rchs1964.com/clients/5/58/580abc73d3aac4ea3a2bdd7c75327783/File/90421473720.pdf In PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/2eeb3e75513ba80d42703c40cd21f9ef/30583158021.pdfIn PDF document text
    • http://fulepmark.hu/nyebu/fulepmark/userfiles/file/58300617075.pdfIn PDF document text
    • http://kubak-ubezpieczenia.pl/userfiles/file/fegulawitosefajido.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/40801507224.pdfIn PDF document text
    • http://sungsam.net/userData/board/file/zadir.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/992b39f42bd4618d8324b8be6baf25b5/45035892685.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/2j91b41kjf2f2chb9dn0on3ac4/16095159083.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160820298879ad---sedadikumobe.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bddbda93071---71373002959.pdfIn PDF document text
    • http://arci-mp.fr/admin/File/37177635739.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/aeeef2dccaab013ac7a8b148021228b8/55952764622.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dc9d9d4fd3---24362708891.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160c093c22c4b3---xalorajudavazubosa.pdfIn PDF document text
    • http://finemetal-cn.com/upload/files/89236537123.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/77b700df0a65d9fbad205cb268609853/kotorofavotovoxi.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/6d14984e59e517e5e6ca9d53418e76e1/62877900948.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/1859ac5770e0f4cd7428c2ab93b2750f/57661314134.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/160b2e74fdf606---sixaturakukiram.pdfIn PDF document text
    • https://armagedonspedycja.pl/files/file/39290999264.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/9m6do8i0tnbdn930191s8g26v1/gekenul.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/c5d9a997269e6f4fc89631d39ad24215/dalijezelo.pdfIn PDF document text
    • http://dzbnf.com/upload/file///27158178705.pdfIn PDF document text
    • http://www.melloecastro.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080f3eae7a6d---tujufixox.pdfIn PDF document text
    • https://tractorpulling-emmeloord.nl/upload/file/wotavi.pdfIn PDF document text
    • https://pointvirgule.ca/upload/editor/file/buzutu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=introductory+functional+analysis+with+applications+by+erwin+kreyszigPDF 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_off0000dbdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBDB 11444 bytes
SHA-256: b3f2d88260e131c19162382c0159e199d64f84458eb9de559fb013ca66eba3d8
font_01_sfnt_off0000f689.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF689 17800 bytes
SHA-256: dacb6dc8e685519d93e4e5e411e4bf56dc3f48cd47ce2fc832653bd3958bd018
font_02_sfnt_off00012549.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12549 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1