Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa8ba7f38a3ddca5…

MALICIOUS

PDF

72.8 KB Created: 2021-04-16 04:13:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 6615c6fa8b0f01d412fa4ac049faaf76 SHA-1: ddd63410580ee9bd82317667b6f2d902734f482c SHA-256: aa8ba7f38a3ddca5d4915b272b5b6cac3387335e70d47e3dc48a49c550a9aaf9
166 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a LOLBin command-execution lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://xajibur.ru/strik?utm_term=success+in+clinical+laboratory+science+4th+edition+pdf PDF link annotation
    • http://texivej.sportsontheweb.net/13169339511.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4494889/normal_6039bbbdcd112.pdfIn PDF document text
    • http://pegoluzalep.22web.org/10358192795.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481406/normal_5fdf31d58f08c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415936/normal_604bb1c17760f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4473023/normal_6008d01a3fcc0.pdfIn PDF document text
    • http://tefuvawilutir.mypressonline.com/novecento_baricco_download.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451742/normal_5fcbfe100e996.pdfIn PDF document text
    • https://static.s123-cdn-static.com/In macro / runtime command snippet
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://033f1a72-e514-447f-b44b-9d234b37386c.filesusr.com/ugd/f05202_138053990dd24b1aaedbc281f34d0d41.pdf?index=trueIn PDF document text
    • https://df1882fa-13c5-42f1-8438-577935b594b9.filesusr.com/ugd/91932b_02c2e6167c6a4596a526dd115bb0fccd.pdf?index=trueIn PDF document text
    • https://9042e326-c85f-44e6-b9b6-0c206471fdba.filesusr.com/ugd/0d2fda_4fa9fe9f5e2142ecbd245cff1a47c484.pdf?index=trueIn PDF document text
    • https://93bb5028-8b17-4c47-8ab9-f46a024b0e86.filesusr.com/ugd/041612_98a2b73159af41ab824e11c8e968a122.pdf?index=trueIn PDF document text
    • https://3a00e800-a8eb-44ae-aafc-ae9aecab8e06.filesusr.com/ugd/1715bf_85cc5d1e3e5e4fdc9d9543d6b587477a.pdf?index=trueIn PDF document text
    • http://namakanexir.atwebpages.com/how_to_do_wave_curls_with_flat_iron.pdfIn PDF document text
    • https://7f58a6d3-5723-489e-a2bd-17fd91e1ddd5.filesusr.com/ugd/655495_1d6a044e0dec4151acc8f5b8bff5891a.pdf?index=trueIn macro / runtime command snippet
    • http://jumebesatupa.epizy.com/vmware_windows_10.pdfIn PDF document text
    • http://dizavinizekabos.rf.gd/acoustic_camera.pdfIn PDF document text
    • http://tigovakidif.epizy.com/streamline_english_book_1.pdfIn PDF document text
    • https://0793e221-2e7e-4176-aae8-4ff4b75d8f7a.filesusr.com/ugd/64bd79_85421e043e714f69a7501f86f5ade67c.pdf?index=trueIn PDF document text
    • http://vajitefafuxuz.epizy.com/photogrammetry_books_free.pdfIn PDF document text
    • https://caf0f927-206f-4b4e-aa34-0dd3da53679b.filesusr.com/ugd/83d902_8a5772d4117347639a2b7e001ed7c587.pdf?index=trueIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD29 5676 bytes
SHA-256: 9877090f4a3d7d4ef3d0b1b1b455be203f140f041145b771e375719ef580e821
font_01_sfnt_off0000f07e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF07E 10832 bytes
SHA-256: 2a78f482835f76965dd3b3475367a31a35053fc0f8c971a29260fd87e13815b7