Malicious PDF — malware analysis report

Static analysis result for SHA-256 b751ec350e326a81…

MALICIOUS

PDF

81.9 KB Created: 2021-07-19 13:17:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 74694f28f0550636b2e48dc2b2baa3d6 SHA-1: aca7b8c1629815b726b2435496cc632cde014b7e SHA-256: b751ec350e326a812337d39149b113493f6d31366e846404118b7608aa925db9
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV detecting it as a phishing trojan. It contains numerous links pointing to compromised WordPress upload directories, indicating a link farm designed to distribute malicious content. The document body is heavily obfuscated and unreadable, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/f58ea1af100b4686bd8a98639b36810e/kemodozafajod.pdf
    • http://pro-group.ru/userfiles/files/27638360198.pdf
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160759867cf1ea---72183719647.pdf
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfb09c7c7f5---20602939376.pdf
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082e7e2c5181---90463058293.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/2f49c71a9afb7a3129c3b08e9f833cc8/tiwisiguvifotira.pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c02b9581d3---161396106.pdf
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/dfnj2eee6ur189k3mfb1e70kth/45270511523.pdf
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/45a4879db9c77f96dd5fd194b78d865e/90393617948.pdf
    • https://capitaleny.com/wp-content/plugins/super-forms/uploads/php/files/5e6cecbf2cd4a06727d756fadf35ac1d/61299683743.pdf
    • http://besttailor.info/ckfinder/userfiles/files/4815196404.pdf
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/e1bka9ikanierq6buhf58skr4i/12056821257.pdf
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e302d930b6---4147375535.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099083189f17---boboroxi.pdf
    • http://ahcxdq.com/uploads/file/300649595045.pdf
    • http://clinicaveterinariasangiacomo.it/userfiles/files/61496734821.pdf
    • http://weilandensemble.nl/ckfinder/userfiles/files/237367338.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/160ad3e7cb2e0b---divofaxikuzivo.pdf
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/vbh3gfu8u2u0agdhq8g1j6dnn5/wekuzexonexipusudu.pdf
    • https://nexusmediation.nl/files/zufavif.pdf
    • http://technoculture.cz/admin/upload/file/kekadudovudavogavegukuwil.pdf
    • https://rajakeempat.com/contents//files/wodenigizulasudesafudatin.pdf
    • http://southfieldhigh.com/clients/a/a2/a202dccd336a30abee2d0a4364b9f07c/File/86197574520.pdf
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/9356963758.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=loops+on+back+of+sewing
    • 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_off0000e048.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE048 16792 bytes
font_01_sfnt_off0000f85f.bin
f445163fb2d329413b37179b3063c482ce6edb0e70cae331d2e186d145374660
pdf-font-stream PDF embedded font (sfnt) at offset 0xF85F 10688 bytes
font_02_sfnt_off000110e2.bin
3727b181c3c84d2b7f8b5b86efa64b5aa6e61e4fdca0875f45ab8930a7633406
pdf-font-stream PDF embedded font (sfnt) at offset 0x110E2 16064 bytes