Malicious PDF — malware analysis report

Static analysis result for SHA-256 55835505e0ad93fa…

MALICIOUS

PDF

76.5 KB Created: 2021-06-26 16:41:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: de26a97cf9a379fd7bcbad72cf26757f SHA-1: 64bdb64cb3879db83a288d70cd2cc19b5078dc76 SHA-256: 55835505e0ad93faca1ed565b3224ffd6f660a430bcfa1fa30db95da251c2e3f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, with numerous URLs pointing to compromised WordPress sites, likely serving as a distribution point for phishing or malware. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nomylo.ru/uplcv?utm_term=perks+of+being+a+wallflower+quotes+the+love+we+deserve
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/160707999905f2---xibofajupefamif.pdf
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/160887e7179727---biwexunupidematawodutoge.pdf
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/rd9opvq85ueqh5np6mi6d0jc9f/laledumolapepuvoboj.pdf
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160ac818f081f8---40134861738.pdf
    • https://soudurelauziere.ca/upload/editor/file/37135160974.pdf
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/2d42994d5bad4ccae50f33425f107730/sonurazo.pdf
    • https://tidurmalam.com/contents//files/56857685932.pdf
    • http://usarsenal.it/userfiles/files/68982417289.pdf
    • http://adria-ex.com/images/blog//file/12719269675.pdf
    • http://bmcnx.com/userfiles/file/38493469028.pdf
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094fed30c1c8---litivagawonugarala.pdf
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/160739f8d1ac75---16493535673.pdf
    • http://campfirewtx.org/userfiles/file/53520024189.pdf
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16080dd476db7b---23138559339.pdf
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160d384092f021---jilimudo.pdf
    • http://agroanaliz.by/upload/editor/files/65091218589.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16083c008733c5---tenarajukaxezef.pdf
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/6tadrbglaa4rrv4866cfjllmr7/9085542538.pdf
    • https://rlvanstory.com/wp-content/plugins/super-forms/uploads/php/files/fc2fd1626155890aa6d0708a203248b9/pebuvikesuka.pdf
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff39404fa7---wekajoseledizanukup.pdf
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609af7da1838f---dosuzijobinupewuvozuzefow.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c796.bin
a800e5f079d0dc7a2acf3f177678323612662d3dbd6218f21ee93da3f16f29ee
pdf-font-stream PDF embedded font (sfnt) at offset 0xC796 11264 bytes
font_01_sfnt_off0000e18e.bin
6709f75240732876210269e8ddf6a857ac8c169a0e4bb734b967547e79314060
pdf-font-stream PDF embedded font (sfnt) at offset 0xE18E 16092 bytes
font_02_sfnt_off00010a84.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A84 16792 bytes