Malicious PDF — malware analysis report

Static analysis result for SHA-256 b50d88bfd3cd4010…

MALICIOUS

PDF

70.0 KB Created: 2020-11-24 19:55:51 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 857b107bfd8821712710d3aa1b7564ec SHA-1: 5b28eb0b54e6435d510c18ea312865642c4b3154 SHA-256: b50d88bfd3cd4010d3f56f2f83606dbb01713a6a85e339703fe3ba1590973904
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, suggesting it is part of a link farm designed to redirect users to potentially harmful websites. The presence of embedded URLs and the heuristic 'PDF_SEO_LINK_FARM' strongly suggest the document's purpose is to drive traffic to these external sites, possibly for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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
  • 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://trafficel.ru/123?utm_term=splendor+in+the+grass+poem+quote
    • https://zekuwatifakaxi.weebly.com/uploads/1/3/2/8/132815855/pafepatabaj.pdf
    • https://viwuwobigoku.weebly.com/uploads/1/3/1/3/131378942/mexobixuvasurelete.pdf
    • https://cdn-cms.f-static.net/uploads/4388272/normal_5fa094a4e33fe.pdf
    • https://cdn-cms.f-static.net/uploads/4365542/normal_5f870bf91531a.pdf
    • https://gixusikowolo.weebly.com/uploads/1/3/4/8/134898106/7463004.pdf
    • https://xovifare.weebly.com/uploads/1/3/4/5/134524114/24deb5a494b168.pdf
    • https://bewapuvin.weebly.com/uploads/1/3/1/4/131453684/a6fbd90d73.pdf
    • https://makonajarozov.weebly.com/uploads/1/3/4/3/134341931/f69c33182.pdf
    • https://woliwejimagevin.weebly.com/uploads/1/3/4/3/134319070/1379046.pdf
    • https://cdn-cms.f-static.net/uploads/4365624/normal_5f8760272c74d.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://s3.amazonaws.com/genijusemu/3816327674.pdf
    • https://uploads.strikinglycdn.com/files/924a5b0a-9551-4a1c-a74d-4a6f4dabf72e/51929555853.pdf
    • https://uploads.strikinglycdn.com/files/8d4e7dc0-b8f7-4b07-a192-ff89e1751399/19458374721.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c8ba.bin
39e5ff86c12bba5a16317384605acc685bbd9969899e6372875579996247cf00
pdf-font-stream PDF embedded font (sfnt) at offset 0xC8BA 5484 bytes
font_01_sfnt_off0000db21.bin
597f8927fa8192e6e9950b9402ee8ae7fa946d07ace82269fa5f624dca381913
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB21 10072 bytes
font_02_sfnt_off0000fd39.bin
1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD39 4324 bytes