Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b43fe7731f17a57…

MALICIOUS

PDF

85.2 KB Created: 2021-10-05 14:26:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 6491770864f814ee7bae7e197d664ba0 SHA-1: f7140488ce6eaf93145ad8fe1f6cebca53c66b2d SHA-256: 5b43fe7731f17a576fff346241fd7d41ea46ce0a15e471722d825d30c63a8dc8
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or link farms, as indicated by heuristics like PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://drafthe.ru/uplcv?utm_term=stiffness+matrix+is+nearly+singular+and+cannot+be+solved+plaxis PDF link annotation
    • http://debten.net/UserFiles/File/wokis.pdfIn PDF document text
    • http://grupopiscis.com/upload/files/6902789816.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/e480f8c1b6ff08d670b64bf30ca81bb2/garokeraxamuvifiliwopujob.pdfIn PDF document text
    • http://tractortools.cz/ckfinder/userfiles/files/5609632824.pdfIn PDF document text
    • http://rund.cz/UserFiles/File/mefuxifife.pdfIn PDF document text
    • https://paeonia.ch/userfiles/files/kilofinoloxel.pdfIn PDF document text
    • http://hidramaco.com/files/files/papakaf.pdfIn PDF document text
    • https://wrd13.com/force/file/81515695130.pdfIn PDF document text
    • http://premiumdrinks.eu/userfiles/92291931372.pdfIn PDF document text
    • http://shannonlakeestates.org/fck_images/file/dimukegalotopiwafur.pdfIn PDF document text
    • https://kiptep.ru/file/22760339443.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/17870376196.pdfIn PDF document text
    • http://aaykpn.com/uploads/editor/files/lotapotax.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/41255736192.pdfIn PDF document text
    • https://gregoryshow.ru/files/file/31128759329.pdfIn PDF document text
    • https://cosanuesa.com/componentes/editor/ckfinder/userfiles/files/wuxavugiwawiwigi.pdfIn PDF document text
    • https://vespaclubcagliari.com/userfiles/file/23646029264.pdfIn PDF document text
    • http://nguyenphat.com/public/default/ckeditor/files/kikupivabuxewep.pdfIn PDF document text
    • http://nhactheducthammy.com/upload/files/84356293260.pdfIn PDF document text
    • http://slavutich-media.ru/userfiles/file/86545647554.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1615ac3666293e---xabazokupigij.pdfIn PDF document text
    • http://beiwendq.com/data/attachment/file/45922211653.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139eda4c17dc---9931459340.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_off0000d51c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD51C 11560 bytes
SHA-256: a60788e6dcde7766a65f4a9ca65309f6020a55af1fcda23b0f735d422d88397e
font_01_sfnt_off0000f020.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF020 24932 bytes
SHA-256: f0b12680bf51ed7fedd3ff1f0082f898c83e0f3d9ddad8c16d19b7b6be410d1a
font_02_sfnt_off00012ed1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ED1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1