Malicious PDF — malware analysis report

Static analysis result for SHA-256 61a8a21651dfb2de…

MALICIOUS

PDF

83.4 KB Created: 2021-03-30 13:13:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 4c6ff31aadc2b54eb485cf5355a98fd7 SHA-1: b920a2ffb4db41e93eb4a6c7041a82f73ffb6ba4 SHA-256: 61a8a21651dfb2de3c20fe870d621d80e5bb49933597632f6819d896ed40c16e
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan variant. It contains an embedded URL pointing to 'jacksth.ru', which is likely used to host a malicious payload or redirect to a phishing site. The document body, though heavily obfuscated, suggests a lure related to an 'entrepreneur diagnostic test'. No scripts were extracted, but the PDF structure and embedded URLs are strong indicators of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jacksth.ru/award?keyword=test+de+autodiagn%25C3%25B3stico+del+emprendedor+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4423752/normal_6002febc8061b.pdfIn PDF document text
    • http://wonder-ita.fun/minecraft_new_update_2020_apkpurevf9pz.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421062/normal_5feda7a157010.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377112/normal_6044def35090d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453329/normal_601e2bcf862f9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412158/normal_603d0dd6ab127.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4485434/normal_5fcb9d1968c80.pdfIn PDF document text
    • http://elerctum.org/50748410557oda0f.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
    • https://37976aa0-f55f-47d3-847a-8d185b13ebf6.filesusr.com/ugd/1d6212_bb8668c699054eac8a3edb8660381f5c.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/babf0838-2f1e-4482-9f60-1711dc0c27db/butoxom.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7d8f5f4c-92ea-4062-96f1-e422d5a0fc63/is_wealth_tax_good_or_bad.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3026fa21-e518-4767-bb41-ab8d57c82815/11196918148.pdfIn PDF document text
    • https://11ca5eb4-0abe-4d5d-8073-3f36f6088e80.filesusr.com/ugd/8b62d8_028732b28f79437985c979fb61ef1515.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vipuxafol/73714560523.pdfIn PDF document text
    • https://s3.amazonaws.com/dipafuxe/missing_alphabets_worksheets_english.pdfIn PDF document text
    • https://b724dda4-e2e0-47c5-811c-ae3b7273578b.filesusr.com/ugd/a1e5ee_e31c4761dfbc4cb586fe1948059b81e8.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/donukadizolin/medication_administration_test_questions_and_answers.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e03d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE03D 5444 bytes
SHA-256: 74ba0f36808482447d795c01fe0924871b96c5e3c67463f7bc0e4c3160594296
font_01_sfnt_off0000f267.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF267 12180 bytes
SHA-256: 599489f79f24a9a65bab9d44ab636b328bcde4e178f89fdea9c73074cd3c54c5
font_02_sfnt_off00011a01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A01 16120 bytes
SHA-256: 6e2ace9a746ee4f9f9ef39c85f1c6b60d38ca409dbc50e4347af3f6b4533fdcb
font_03_sfnt_off00012ede.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EDE 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c

Open this report in the interactive analyzer, or submit your own file for analysis.