Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a3bafa7eb0cfe5a…

MALICIOUS

PDF

84.2 KB Created: 2021-05-30 11:22:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 23b8c173fefb35f696d640efe51536bb SHA-1: 92f8290a89887c98cd1117150989edf389be8025 SHA-256: 4a3bafa7eb0cfe5a9c3c989d72618d7114aae39537c4a35e2bf22fb98b84ca68
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting services like Weebly, indicating a link farm or SEO spamming operation. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or distributing malware via these links. The presence of multiple external URIs and the overall structure point towards an attempt to exploit search engine algorithms or trick users into visiting malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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 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.
  • 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://maypoin.ru/123?utm_term=idsa+meningitis+guideline PDF link annotation
    • https://vabemeraronoj.weebly.com/uploads/1/3/1/4/131452983/mojiwoxibel_fumake.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416501/normal_604b3a262475e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366947/normal_606403f59d7f0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418170/normal_603d19c4c010c.pdfIn PDF document text
    • https://lijupumo.weebly.com/uploads/1/3/4/4/134496400/1733140.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487658/normal_604d03c1bd841.pdfIn PDF document text
    • https://zufuleruzu.weebly.com/uploads/1/3/1/6/131637307/bd08cadc2.pdfIn PDF document text
    • https://xawewidijaxiju.weebly.com/uploads/1/3/4/2/134266046/viparalis.pdfIn PDF document text
    • https://towizitubozabo.weebly.com/uploads/1/3/5/4/135400713/fd9338a0e9e01.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368243/normal_60374b37d90c8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459326/normal_600bcc159e5fb.pdfIn PDF document text
    • https://kusavavatixe.weebly.com/uploads/1/3/4/8/134878613/78ac5a7271f4a8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402740/normal_601903ba0a970.pdfIn PDF document text
    • https://defasoxajex.weebly.com/uploads/1/3/1/4/131405962/2543477.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/7b3317c8-4c08-4308-a4c8-f658a161be6e/62177330592.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0bcaf84d-294c-4184-865f-a3f6e6a26976/nekaladulinunabuxoj.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f920b7f7-e836-4981-a594-ac26a001f502/95979520672.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f5ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5BA 4988 bytes
SHA-256: df746708f3d6776e4ff972e78b99878199a025759f61f409be03e14c9cc5a604
font_01_sfnt_off0001069f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1069F 12364 bytes
SHA-256: 0c7516ff177f2367ffe47ee2c6e60b511848c6a43eb3b96351bd205172612abd
font_02_sfnt_off00012e48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E48 16204 bytes
SHA-256: a95eff378c135b1ab40d10b3cd1da1bafbc07f86005f57898d079c90d712ddbd