Malicious PDF — malware analysis report

Static analysis result for SHA-256 c163cd099042deef…

MALICIOUS

PDF

81.7 KB Created: 2021-05-29 11:24:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: d2bbe7c53b1501406882c385bd75ff71 SHA-1: d7dfff76eaf06fd0e4fa8cbad0f02b80a6889376 SHA-256: c163cd099042deefb0bf6601ea687e1815800659e4c9b9cb2ee0d4bca3170707
214 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file was flagged as malicious by multiple heuristics and a machine learning classifier, indicating it likely exploits a vulnerability or attempts to trick the user. The presence of numerous external PDF links, including one to a known malicious redirector, suggests a link farm or SEO poisoning attack. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of an attempt to redirect the user to malicious content, potentially leading to further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://yafferge.ru/wb?keyword=black%20skin%20white%20masks%20pdf In PDF document text
    • https://cdn-cms.f-static.net/uploads/4371247/normal_602a1e66d32b0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370055/normal_604657dbe9d77.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369774/normal_6019c597393b0.pdfIn PDF document text
    • https://bobiguwifuza.weebly.com/uploads/1/3/5/9/135966914/kugogibuzedimugiga.pdfIn PDF document text
    • https://nafesidupige.weebly.com/uploads/1/3/2/6/132680955/bupusokimotig_pagamedorixamu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420752/normal_5fdd78e02b6ca.pdfIn PDF document text
    • https://rilopogikumifo.weebly.com/uploads/1/3/4/3/134320310/xegularafe.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4457857/normal_5fcc9440ad88b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465392/normal_60302cd6b0856.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4428043/normal_5fe40e6da77da.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408865/normal_5fea3dc0813f3.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://uploads.strikinglycdn.com/files/3bbd04f4-67d1-496f-90a7-7d7c6b444d9f/lixixodalalaxizipeziro.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d7fa008a-67f1-453d-b7ac-f22f6630da8c/27012056093.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e711f13a-11de-4280-885e-e9c6ba008253/how_to_make_a_beautiful_ribbon_gift_box.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/deed3632-748b-43eb-9b95-805637c2670d/bosch_300_series_dryer_keeps_stopping.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/66041524-1f0e-4dc7-bcc1-28b39b0b7f20/roland_td_11kv_user_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/84e90447-c291-4cc2-9f05-e20e52138bc6/rajiditunutevalatuvaxuxip.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e2eba67b-d30c-4946-a60d-4cbdd26fbba6/lesopaduv.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b59cca49-00c2-4c63-9477-bd3457b4e7a3/ruzusoto.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cdfef46f-cf26-423b-ba20-5986dfa3c91d/how_to_put_screwdriver_bit_in_black_and_decker_drill.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f543.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF543 5184 bytes
SHA-256: b67f90b3b1693801db8b2426d3abf9c483185fb33ac04a6a11ad1558b9e754dc
font_01_sfnt_off000106c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106C9 10900 bytes
SHA-256: 8864e6a9b05b55301b9fcfdb9ff1ef635d2185868dedb7e9b3d4199f02639209
font_02_sfnt_off00012b77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B77 4324 bytes
SHA-256: 7f6049e5011acf0e8581793f2bc2bb947aac2929fdb77abc318b2a6155c1ef71