Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a6b4344425ca280…

MALICIOUS

PDF

73.9 KB Created: 2021-03-30 22:05:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ed7b44d172034bf2194bc180485900d9 SHA-1: 7781fb18da03d6a4492841d11121f8bbc61a455c SHA-256: 4a6b4344425ca2800039e50d15471942514a85a8f60a8776083d5a6ae375a02b
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded external links, identified by the PDF_SEO_LINK_FARM heuristic, suggesting a link farm or phishing attempt. ClamAV also detected this file as Pdf.Phishing.Trojan. While no scripts were explicitly extracted, the presence of numerous external URLs and the phishing detection strongly indicate malicious intent. The document body is heavily obfuscated and unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://zajinet.ru/strik?utm_term=how+do+you+turn+off+airbag+light
    • https://static.s123-cdn-static.com/uploads/4405186/normal_5fc93ce801c14.pdf
    • https://cdn-cms.f-static.net/uploads/4427821/normal_5fdc2036d3a0c.pdf
    • https://cdn-cms.f-static.net/uploads/4366306/normal_601bce1c37d97.pdf
    • https://cdn-cms.f-static.net/uploads/4490523/normal_602cee3ebe434.pdf
    • https://cdn-cms.f-static.net/uploads/4470552/normal_6018645edf4e7.pdf
    • https://cdn-cms.f-static.net/uploads/4388842/normal_601e6821123c8.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/lokijuronig/assembler_jpg_en_en_ligne.pdf
    • https://s3.amazonaws.com/xijalovelokolep/opera_mini_web_browser_cepat_apkpure.pdf
    • https://b09d99c6-da67-4e55-b5b3-baceba093817.filesusr.com/ugd/a69c6c_e555e41ec16843aebcd37a52528f521b.pdf?index=true
    • https://168d2a81-f750-40c6-a653-3787650f980d.filesusr.com/ugd/3bcfef_3925072b10f14bdf992cb2069643063e.pdf?index=true
    • https://78e27e65-9996-4239-a63d-7a21722db537.filesusr.com/ugd/03f576_9c28af6a60284d02b7fbabb43f0fa8e9.pdf?index=true
    • https://6bc61794-ec17-45f1-96eb-8bed4cd57308.filesusr.com/ugd/217b8a_688a55f4a5f34721bba9e716a25e684b.pdf?index=true
    • https://c03439ef-6557-4199-865e-586791a52b6c.filesusr.com/ugd/6bb4a2_3b9023d29d0140f588c2da9ac8b87660.pdf?index=true
    • http://zimunumiwu.epizy.com/vexufora.pdf
    • http://dovitunazimaze.epizy.com/11441553096.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_off0000e508.bin
3d303f00096f7f1dcf4fb373ee8460e9773b4d480da28bc35129eedb920f85d2
pdf-font-stream PDF embedded font (sfnt) at offset 0xE508 5288 bytes
font_01_sfnt_off0000f711.bin
6b787ec7afbbec1d8e7ca0e560ca0126481147c1714f7ef0019d617fcbc529ef
pdf-font-stream PDF embedded font (sfnt) at offset 0xF711 10528 bytes