Malicious PDF — malware analysis report

Static analysis result for SHA-256 83a88ed1a45a116a…

MALICIOUS

PDF

94.5 KB Created: 2021-06-21 02:08:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: c751074ca19684bce5cf737a1c6f7fbf SHA-1: 495c86bfe0c979b420f940bf68c09d5f3a2f4b09 SHA-256: 83a88ed1a45a116a0b79ab30bb2f1159f8da2e0ee6a793c51c23bd0b92c484c0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging embedded JavaScript for exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://ketchas.ru/uplcv?utm_term=korean+colour+test+personality PDF link annotation
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/16079c32642ea2---883567563.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/43210517851.pdfIn PDF document text
    • https://eberli-medical-supply.ch/upload/file/7926013107.pdfIn PDF document text
    • http://hurtmar.pl/Upload/file/76253322850.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b2daa21bd8d---vokubatexetiru.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/noed71851u63eude7bhger40q1/xarifagafegadanemurevuz.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/f94a72b514a97b90e41411cfe3df83d1/2165299780.pdfIn PDF document text
    • http://www.conectadoscomdeus.tv/arquivos/file/63039160180.pdfIn PDF document text
    • http://sunjewelsonline.com/userfiles/file/xomexazokuseruvebozaladob.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/ba937e42f72ae6108076ad2286505fc0/69301948081.pdfIn PDF document text
    • https://ctapigroup3.com/contents//files/tufivutegotuwowusefadug.pdfIn PDF document text
    • http://gdbchurch.com/clients/43262/File/59931847872.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/f0183ddebc27828539b28afddcf0d8aa/50240233938.pdfIn PDF document text
    • http://russkiivopros.com/images/FCKeditor/file/rokulakupagofikav.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/da8f6b30b4a2f7e9a39ebb6df757a86e/71660487857.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010f40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F40 5884 bytes
SHA-256: 0342317974cc2fd4579fa4cb2afbba6940a87ce984d5894fb6ce31f3c70ced1c
font_01_sfnt_off0001238e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1238E 4880 bytes
SHA-256: edf40ba6dec4a3078941718fc648d754ab7a0f5468171efaeb118814e7b83562
font_02_sfnt_off00013439.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13439 12720 bytes
SHA-256: d39cb8cdc8d3970442ac4c49a888a7f63471a8bec305cd34471b65ca2fc7b724
font_03_sfnt_off00015e4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E4F 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c