Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba4b58d4a249f951…

MALICIOUS

PDF

87.1 KB Created: 2021-06-25 15:07:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b4bbc07ac0f10b0c0c01b9a7eca27d4e SHA-1: b45f374118016c113f757830f43473582133108d SHA-256: ba4b58d4a249f95121db9ab6210955564ca4f61048d33fb5ac63db48dcc245eb
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs pointing to compromised websites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic confirm the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://coretry.ru/uplcv?utm_term=multi+armed+bandit+machine+learning
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/dde9c8466aa88979f8aef1bcda35136a/69421592189.pdf
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087e16b9202e---28195744696.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d433fe5338---nujonugujet.pdf
    • http://kimyasaldubeller.com/upload/ckfinder/files/82834954686.pdf
    • http://akicgiyim.com/userfiles/file/novozapufok.pdf
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/35432b37de0d8c9d3d16cfaad25d738a/zizesuxugip.pdf
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609ad75287631---86623422891.pdf
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/8c4b6633f82fe58f15d835f92c158a4a/banejavat.pdf
    • http://nakajima-ya.com/upload/save_image/files/94417811975.pdf
    • https://goldenapp.net/file/89359583344.pdf
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/f2bnde3q9dpmp227vf7bvpdhp3/porabemometize.pdf
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/21c86f1389edd5873b68030d8cc7d9a3/dojivepitawugu.pdf
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160701f17062ac---45500678517.pdf
    • http://tuning-zone.eu/userfiles/file/gubokovasusetutuvunujoj.pdf
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/eb0ikv7gvn7gl7e64vf3fdh427/vovonilijofodubavumonu.pdf
    • http://zhengfutz.com/v15/Upload/file/20216211942212675.pdf
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/327118153ad440f3369f0c3040f2d13a/pupigenozenunoveg.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_off0000ed85.bin
f8051edad1909120e8f3de243e619c123868caa43ba6974227e2852e0fd7c7fe
pdf-font-stream PDF embedded font (sfnt) at offset 0xED85 10760 bytes
font_01_sfnt_off000105ce.bin
5be093a21f6124d5aec7415afcdad1dfc2980818c96c3ba8e8f1c58a89e4026a
pdf-font-stream PDF embedded font (sfnt) at offset 0x105CE 18248 bytes
font_02_sfnt_off00013628.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13628 16792 bytes