Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b08fb5d37e051c3…

MALICIOUS

PDF

82.1 KB Created: 2021-07-02 09:20:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1b4ac5e80d96f619984429ffb483aba4 SHA-1: c07adf7a8a3b577bd456191f02866e328f04b9ac SHA-256: 2b08fb5d37e051c323100554b65accdd7b28e9146356464341bb92666ad47575
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV detecting it as a phishing trojan. It contains numerous embedded URLs that form a link farm, pointing to compromised WordPress sites and disposable hosting, suggesting an attempt to redirect users to malicious content. The document body is heavily obfuscated and unreadable, preventing a clear understanding of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://cructi.ru/uplcv?utm_term=difference+between+opinion+and+argument
    • https://annjulieskarpmo.com/userfiles/file/pavij.pdf
    • https://makeswebsites.com/clients/c/c8/c8c605999f3d8352d7bb792cf3fdb25b/File/22802250094.pdf
    • http://aggengr.com/uploads/CMS/file/ninisaxizojufi.pdf
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1609a7dde58df5---14394795588.pdf
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160808521b656a---gosaxip.pdf
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/e10e0b7c983276af2f7465c18ef2509d/24644575877.pdf
    • https://kurishupally.org/userfiles/file/14183310290.pdf
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/uqai2i2ov4aaqg56cms7d0c7at/lavuju.pdf
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c64c76aef86---63844152662.pdf
    • http://asustainable.com/global/file/nokenulazeni.pdf
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16086ff56f2617---zupire.pdf
    • https://szud94.hu/img/sajatfile/files/74566404877.pdf
    • http://immodraft.nrw/images/architekten_agentur_images_/file/wolukalitoxadujofedij.pdf
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/3665c59e7ceedbddb71a7413d7ce2c7a/41337237812.pdf
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/03a3ddadb3b6468058df2b4dba8ab0ce/bubezesudododezukonikibu.pdf
    • https://paklya.su/design/img/upload/file/petifowuki.pdf
    • http://bharatdarshan.net/rgroup/ckfinder/userfiles/files/69402123042.pdf
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/39b64fec22f4df887bb766fcf5bc75c3/zotodolemopem.pdf
    • https://bbpartner.cz/userfiles/file/7543108332.pdf
    • http://armanetti.com/images/guraf.pdf
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/60795414338.pdf
    • http://year-c.com/upload_fck/file/2021-6-14/20210614080324199608.pdf
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/7047c3199c1f63cdb8c225b934f6baa0/kelinogimuzotiriroxepaf.pdf
    • http://mobilesamara.com/img/files/file/73974108920.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_off0000dc31.bin
a305f7dcca550c3e1da604851cf7bb8bfadb79509fdb2aec22081c77c9283ad9
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC31 17048 bytes
font_01_sfnt_off000107ad.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x107AD 16792 bytes
font_02_sfnt_off00011fc4.bin
549a91e0790cb43a4a9df67a863f5da4ea0e3d140a5ea1f23504b58f8df82ef4
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FC4 11076 bytes