Malicious PDF — malware analysis report

Static analysis result for SHA-256 3824493cb0199b25…

MALICIOUS

PDF

81.5 KB Created: 2021-06-02 08:11:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: c3d6ac093305af5d8f7ffc6219843a96 SHA-1: 6fe6a935277768716595d945133c2c9c6ff90f15 SHA-256: 3824493cb0199b2525ed41a6d3f9b06c820bd4030d9075de411467dd36d5de26
186 Risk Score

Malware Insights

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

The PDF file contains a significant number of external links, many hosted on disposable domains, suggesting a link farm designed to redirect users. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' indicate this behavior. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://pistant.ru/pbw?utm_term=shoprite+donation+request+form+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4452834/normal_5fe1757f739c7.pdfIn PDF document text
    • https://zerevodajerut.weebly.com/uploads/1/3/4/5/134502997/398a7d44.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421209/normal_6057e66a1ee94.pdfIn PDF document text
    • https://sudunubi.weebly.com/uploads/1/3/4/4/134496389/bonofiw_kenuratefosij_lizazosi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378618/normal_60605e350d337.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485161/normal_60273f6a6ef28.pdfIn PDF document text
    • https://tujupanex.weebly.com/uploads/1/3/5/3/135333196/1712860.pdfIn PDF document text
    • https://nitowapesapu.weebly.com/uploads/1/3/4/4/134442046/8049714.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4489717/normal_60095ce2702e1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421354/normal_6047fb4303159.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471238/normal_6041206fbd71b.pdfIn PDF document text
    • https://jetosiwer.weebly.com/uploads/1/3/4/7/134767378/zudalomaku.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393624/normal_604acda93bfc8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475208/normal_601973521efdd.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/b41d3599-0a9f-4f1d-9abc-9de181c32444/65691837478.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/289b9c6c-2fa0-4bdd-8b8c-cc660b740b00/xeloxujudemis.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2f889197-ecfc-4fa7-91f8-130bfb892332/do_grandfather_clocks_increase_in_value.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/acac95ac-07ab-4d7a-9f66-69ef4adb38fc/tufed.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8cc251a7-0186-4ca8-92ed-4ebe3d4a24fc/kevaralujijif.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e0fb511e-f9d6-4f36-a3cd-b12c57eee596/why_is_sexual_reproduction_better_than_asexual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/764168c2-469b-46ad-9664-46aa14575042/one_minute_manager_book.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001013c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1013C 5476 bytes
SHA-256: b3fc4735c9d87353dd11cd18689cff53aa0dd7fb347be0dcd2bff3abf78a89f9
font_01_sfnt_off000113b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113B1 10312 bytes
SHA-256: eae3e7ec163a880f63a08502c013ce988f21fe0618315af121064c202ade1748