Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa13b3f48a512403…

MALICIOUS

PDF

69.0 KB Created: 2021-06-11 03:30:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 861f5f9fb33d1d890d38783e172d9392 SHA-1: 8cad1a0ccf257b34b72f11b90fcee672b81f9fec SHA-256: aa13b3f48a5124032255ca5430b3571d35ba441612d1744f16a5fb3802bce275
186 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV and an ML classifier. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm or phishing operation. The document body is heavily obfuscated but contains metadata indicating it was generated by wkhtmltopdf, and the presence of embedded URLs suggests an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://catamma.ru/pbw?utm_term=cartoon+film+tom+and+jerry PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4413370/normal_605a1493015f6.pdfIn PDF document text
    • https://bewarovawizijus.weebly.com/uploads/1/3/4/4/134454629/fawajenex.pdfIn PDF document text
    • https://vowopazi.weebly.com/uploads/1/3/4/0/134096587/rexewaf.pdfIn PDF document text
    • https://niwesebo.weebly.com/uploads/1/3/4/4/134401773/1338159.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4394060/normal_60c1e22d296d7.pdfIn PDF document text
    • https://kimonasisu.weebly.com/uploads/1/3/5/4/135400987/9475368.pdfIn PDF document text
    • https://walidixigojal.weebly.com/uploads/1/3/4/5/134595726/8556391.pdfIn PDF document text
    • https://luxaxezasu.weebly.com/uploads/1/3/1/3/131398230/27824851.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/133acfa4-a167-48ec-9bd7-8b2ac09cf44c/which_samsung_tv_is_better_6_series_or_7_series.pdfIn PDF document text
    • http://xumamiz.pbworks.com/w/file/fetch/144696360/how_to_reset_my_water_softener.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c9265083-27b6-4eb0-bc6c-2376af67c90c/lesson_5.2_practice_c_geometry.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e1688ae5-9e20-44d5-b33c-feca28a95ade/39371671714.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b8090c95-a735-4507-9246-d97680ec8853/dunuseroles.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b30d817d-31de-44cb-b66e-4239bb092540/canon_70d_magic_lantern_clean_hdmi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dcd10c8b-f9bc-43f7-a8c2-a6c2b5c73e93/72436829637.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/03890f07-9a7e-4409-a232-d5d621fd9d54/4923607783.pdfIn PDF document text
    • http://rimogeto.pbworks.com/f/22846851166.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_off0000d172.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD172 4956 bytes
SHA-256: 25ffb43953224a6714b9b1e93a17540f177d9a4280a68b02a3f3455ad36f6132
font_01_sfnt_off0000e245.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE245 11040 bytes
SHA-256: 6225bbac77dd27281e7f5d39594c8968a716b5f3f0c0065af0bc27859cc58c9a