Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4c91b7ce86a1de3…

MALICIOUS

PDF

83.9 KB Created: 2021-04-10 00:45:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e555cf7c94cd2346d9240c8edf2e1809 SHA-1: 28f6d7efc98ab769389a95bcb3823e70603514b2 SHA-256: e4c91b7ce86a1de32ab3f6773cd75d43d4382e96012ca063aeca2a8944984681
156 Risk Score

Malware Insights

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

The PDF contains a link farm and is flagged by ClamAV as Pdf.Phishing.Trojan. The document body, though heavily obfuscated, suggests a lure related to downloading software. The presence of multiple external links, including one to zajinet.ru, indicates a likely attempt to redirect the user to malicious content or a phishing site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://zajinet.ru/strik?utm_term=how+to+download+accu+chek+compact+plus
    • https://cdn.sqhk.co/vesagivara/yibqqii/alto_s_odyssey_apk.pdf
    • https://cdn.sqhk.co/jixuvepabu/DxjahjG/70735646553.pdf
    • https://cdn-cms.f-static.net/uploads/4476437/normal_60501e15a747b.pdf
    • https://cdn.sqhk.co/fekolisuzub/whiS6KI/28747475318.pdf
    • https://cdn.sqhk.co/woberimi/s9gcgjK/8507755522.pdf
    • https://cdn.sqhk.co/xumirikebixo/hjaOgfm/10130280246.pdf
    • https://cdn.sqhk.co/gujowaxexag/igcHxgp/cyclebar_midtown_raleigh.pdf
    • https://cdn.sqhk.co/fubafonu/jdjcIjd/4408204559.pdf
    • https://cdn.sqhk.co/befulirawid/icjdsn5/68424190771.pdf
    • https://cdn-cms.f-static.net/uploads/4384832/normal_6028667749756.pdf
    • https://cdn.sqhk.co/farafakilof/ja2WKw1/mexan.pdf
    • https://cdn.sqhk.co/degawatoze/C1XjaIG/logonuvijukifazekujajat.pdf
    • https://cdn.sqhk.co/lisesemafo/heghpwS/89855755332.pdf
    • https://cdn-cms.f-static.net/uploads/4481157/normal_605bfff06c1b8.pdf
    • https://cdn.sqhk.co/zidexamuwela/cghUmIu/36106447762.pdf
    • https://static.s123-cdn-static.com/uploads/4459941/normal_5fee7e2d5d41e.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://dbba0f06-1911-40f0-8c80-a2638c7f81cc.filesusr.com/ugd/b13fd1_333a0d2861c24034be176c1556595f59.pdf?index=true
    • https://s3.amazonaws.com/jevelel/13262270629.pdf
    • https://44bb6ee8-a0fe-4f72-890f-0f0a2fec05cf.filesusr.com/ugd/b65acf_4d3d952698424837aab2525c9d7aae68.pdf?index=true
    • https://s3.amazonaws.com/jovekus/fema_is-_100._c_test_answers.pdf
    • https://351e5f87-f9e5-4015-92cd-d601692b9ec3.filesusr.com/ugd/a0d0d3_f71592e0949b4e04a84af43a5f2e3d3d.pdf?index=true
    • https://7043ee2c-bc2d-4d46-b82c-b0075177c1aa.filesusr.com/ugd/f862b5_08a95ed916eb4a0e87ff9a341a8e125e.pdf?index=true
    • https://s3.amazonaws.com/gelawiweza/superficial_vein_thrombosis_treatment_guidelines_accp.pdf
    • https://s3.amazonaws.com/gajakelegeza/what_iced_coffee_should_i_get_at_dunkin_donuts.pdf
    • https://s3.amazonaws.com/wutezigojuxi/linear_programing_word_problems_worksheet.pdf
    • https://734e8db3-b9db-457c-abaa-08c06218e7ae.filesusr.com/ugd/f6bb82_aafe68fc117a42eda7a08af7b79500eb.pdf?index=true
    • 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_off000108be.bin
bde995c71dd33eea7fa2a45903c56dca20294590aae5213b9dc49d73709a3119
pdf-font-stream PDF embedded font (sfnt) at offset 0x108BE 5336 bytes
font_01_sfnt_off00011acc.bin
3cdcef7e6f2738bb06d0e778d7321acf29d8ca1576ef08c3e9f8981dea6eac86
pdf-font-stream PDF embedded font (sfnt) at offset 0x11ACC 11300 bytes