Malicious PDF — malware analysis report

Static analysis result for SHA-256 993075604b3d9686…

MALICIOUS

PDF

87.0 KB Created: 2021-08-12 07:12:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3ba61a34db1a374fa4173a22017596bb SHA-1: a115bd62e84c46183c739ce4cad43377864a2485 SHA-256: 993075604b3d9686822c5c445e98ffd3426b366d09cc463449210cca2e70d237
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, which in turn host other malicious PDFs. This suggests a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for initial access via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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 https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/21337caecd8270cf18a70608bd8e74b9/kokoji.pdf In PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6e3149999---bamarominafetuseliden.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-5-2/20210502092606605742.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bac894bcabb---2781969815.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/39427416e847f7783788dd3424f9af5f/fafanugezewokege.pdfIn PDF document text
    • http://rainesclassof1980.com/clients/3/31/314d3ac3c31ee16cfc8f78d457af0ebc/File/gilakipilatofuvowema.pdfIn PDF document text
    • http://intemhathanh.com/img_duhoc/files/78497478333.pdfIn PDF document text
    • https://aldurra.ly/images-editeur/img/file/61333812569.pdfIn PDF document text
    • http://cezanart.com/userfiles/file/29821553209.pdfIn PDF document text
    • http://phuongdonggolf.vn/app/webroot/uploads/files/sujegudazirajafunekiwo.pdfIn PDF document text
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/a662n6h2ubd1ar8eo1dkshi7gc/52598911789.pdfIn PDF document text
    • https://atlaskvartir.ua/data/uploads/files/12375967865.pdfIn PDF document text
    • http://agrostroi-proekt.ru/ckfinder/userfiles/files/22230441857.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021072704373573499.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/480fc719181f6937f1311a6c646a9fc3/kawufomapabiru.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/161030af304c45---32449031694.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160d2db72e4bba---81514323779.pdfIn PDF document text
    • https://xn----7sbbjg7ctfs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/f2c2609026fb96a61e13052608f249cc/7483560005.pdfIn PDF document text
    • http://uleshuzatshop.hu/files/file/gojumofifokirujip.pdfIn PDF document text
    • https://mujeresenmovimientoplus.com/userfiles/file/67218705601.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/8e6c6c0d4c341c44c62a1fd11a2dbd99/satipupevubel.pdfIn PDF document text
    • https://postelezmasivu-olomouc.cz/ckfinder/userfiles/files/gerawovuwotajekedizivov.pdfIn PDF document text
    • https://www.wflorlando.com/wp-content/plugins/super-forms/uploads/php/files/9f14bde91e62c087b2c8911668672f71/45351201945.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=what+size+bat+is+used+for+tee+ballPDF link annotation
    • 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_off0000f0e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E2 10640 bytes
SHA-256: 7dc6f11461d5eac1ada8693bf49ce02162ad8a99b4f522a8283c92d41dd10b9f
font_01_sfnt_off00010964.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10964 16996 bytes
SHA-256: 5c1747e681aa1ce8b78140488a4df6b5efeb385ff1a0343a97eca98e98ae28b9
font_02_sfnt_off00013529.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13529 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1