Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f16c1d6d8a15256…

MALICIOUS

PDF

74.5 KB Created: 2021-08-28 08:41:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 84437e5f39036f2ec3b0c4405417d358 SHA-1: c7ca7008dd8a6aa43ed01575373c9dcd60a394b9 SHA-256: 3f16c1d6d8a15256b926f8088be5b752c3de800e7db0c20257af6e7847c8127f
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a phishing or malware distribution scheme. The presence of embedded URLs and the nature of the heuristics point towards an attempt to redirect users to malicious content, likely as part of a spearphishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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=12th+commerce+book+keeping+%26+accountancy+textbook+pdf+2020
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/cc6ef5734375dad5f64ffa8070f1ea78/36517657234.pdf
    • http://olympiad-bigben.ru/ckfinder/userfiles/files/venasuxivisifiwo.pdf
    • http://blfimmobiliare.com/userfiles/files/mogikokodadokuteliluno.pdf
    • http://ural-resyrs.ru/data/file/83536556842.pdf
    • http://location-venise.com/italie_documents/files/wikanit.pdf
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607e458bf0d47---13637833612.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c1beb63116c---viruvot.pdf
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/03aef6c729ac0dca8d39324f273af3e8/maguguwezoturixiwufug.pdf
    • http://erdivigado.hu/userkepek/file/bikepekexabinuj.pdf
    • https://capital-publishing.com/ckfinder/userfiles/files/givenusugikunagezivatogik.pdf
    • http://serdceprirody.ru/userfiles/file/dozifalasizigezovajuvubek.pdf
    • http://euro520.net/userfiles/file/1625353818128764781.pdf
    • http://blossomtour.net/FileData/ckfinder/files/20210814_BF668A380C5646C2.pdf
    • https://stratasphere.online/userfiles/file/68598895648.pdf
    • http://isystem.hu/ckfinder/userfiles/files/50666658111.pdf
    • http://reclamesticker.nl/images/uploads/file/bonimesax.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/1k6d91go2k1t0qo2oj8h2fiqs1/34100831890.pdf
    • http://www.deep2001.com/images/library/File/53964767324.pdf
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/fed649804c4a503c45c8be4880ad127e/60630088780.pdf
    • http://pivotal-technologies.com/userfiles/file/punupamijirimalu.pdf
    • https://ruedi-leuthold.com/userfiles/files/6495323052.pdf
    • http://smartvoicecom.com/userfiles/67858272224.pdf
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/1610ae2501c8f7---41755243855.pdf
    • http://seritour.com/rsm/files/nezawidej.pdf
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/16117b81f37993---48135304168.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_off0000c166.bin
afcc491c4937fc8b38a118470ed35d4f97d3e44c50315c076e84d639176569cb
pdf-font-stream PDF embedded font (sfnt) at offset 0xC166 10752 bytes
font_01_sfnt_off0000d9bc.bin
f6a0990f866a2eb3fafeda8ff351e6bebc5aec71089e9548acffc009810fead4
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9BC 16280 bytes
font_02_sfnt_off000103a5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x103A5 16792 bytes