Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b23441728407136…

MALICIOUS

PDF

79.0 KB Created: 2021-05-20 17:06:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2bd6e3a3e33b07f68b2ab16595c210fd SHA-1: d1d69449435f6ffee78ec1d9f05878b3c8e345d4 SHA-256: 7b234417284071360874efdb42832c58f5ff6f5dbebcb57337b2e3db66935d0f
156 Risk Score

Malware Insights

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

The file is identified as malicious by multiple heuristics, including ClamAV and an ML classifier, with a critical finding of a PDF link farm. The embedded URL `https://jacksth.ru/strik?utm_term=propiedades+quimicas+de+los+alquenos+hidratacion` is a primary indicator of malicious intent, likely serving as a redirect to a phishing or malware distribution site. The PDF structure and the presence of numerous external links suggest an attempt to manipulate search engine rankings or distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://jacksth.ru/strik?utm_term=propiedades+quimicas+de+los+alquenos+hidratacion
    • https://cdn-cms.f-static.net/uploads/4453764/normal_602e1b0b1c3fa.pdf
    • https://static.s123-cdn-static.com/uploads/4465025/normal_5fe4a0c904894.pdf
    • https://cdn-cms.f-static.net/uploads/4424997/normal_5fd7743ab682b.pdf
    • https://cdn-cms.f-static.net/uploads/4462339/normal_603a02d4879dc.pdf
    • https://cdn-cms.f-static.net/uploads/4416318/normal_60161210d87b7.pdf
    • https://tubozabuzimez.weebly.com/uploads/1/3/4/8/134878922/gonad.pdf
    • https://cdn-cms.f-static.net/uploads/4471114/normal_60342787af7aa.pdf
    • https://cdn-cms.f-static.net/uploads/4501656/normal_600a0480448f7.pdf
    • https://cdn-cms.f-static.net/uploads/4368471/normal_601f32ea5959c.pdf
    • https://nedidibizexoba.weebly.com/uploads/1/3/0/9/130969065/4196102.pdf
    • https://static.s123-cdn-static.com/uploads/4483873/normal_5ffbaa2f1cb61.pdf
    • https://kiwuvewe.weebly.com/uploads/1/3/7/5/137509443/likup_torigor.pdf
    • https://zinimokukaz.weebly.com/uploads/1/3/6/0/136053997/b382a.pdf
    • https://juladugalevatib.weebly.com/uploads/1/3/4/3/134385664/jasiduvu.pdf
    • https://static.s123-cdn-static.com/uploads/4388424/normal_5ff85bb7e9595.pdf
    • https://komuwewolidixat.weebly.com/uploads/1/3/4/8/134871085/964990.pdf
    • https://cdn-cms.f-static.net/uploads/4500199/normal_605c6cc8bbda0.pdf
    • https://cdn-cms.f-static.net/uploads/4409110/normal_601604855daa4.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/f9252265-06a2-4bd2-bfa0-858f2c5c02a9/arabic_bible_verses_images.pdf
    • https://uploads.strikinglycdn.com/files/2f014f1e-8e51-45f8-819a-10bce8ee08e1/12489847089.pdf
    • https://uploads.strikinglycdn.com/files/c9add881-f0d6-4a6c-a0f2-b8d62e29dba1/mamiya_rz67_price_in_pakistan.pdf
    • https://uploads.strikinglycdn.com/files/e3b91c92-7baf-45bd-a6a7-e3c16641545c/bokijozujab.pdf
    • https://uploads.strikinglycdn.com/files/6fbefa00-9edc-4c0b-b8b5-aa6beffbe53c/lusuwawin.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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f3d9.bin
38b5486d915c50f748b50d63acb90a12d52bafde9f6f65d0a11b779d1fe587a8
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3D9 5440 bytes
font_01_sfnt_off00010625.bin
0b7de1cd8cfb1b7ab27e5861153df559cefc17f1f7c8a7838f6e399eef1ccad7
pdf-font-stream PDF embedded font (sfnt) at offset 0x10625 11944 bytes