Malicious PDF — malware analysis report

Static analysis result for SHA-256 f42f910f223e52e7…

MALICIOUS

PDF

77.8 KB Created: 2021-04-14 16:15:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 4d328bce3d7c4933bdc563b5506a55b8 SHA-1: 2d43aa80a7ff0134f05e1f90689a582e9bcd971f SHA-256: f42f910f223e52e73083a567c110b0d92cb56ea60b5267f635713543d0d2fb53
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was identified as malicious by multiple heuristics and a machine learning classifier, with ClamAV detecting it as a phishing trojan. The document contains a large number of embedded links, many pointing to disposable hosting and redirectors, indicating a link farm designed to lead users to malicious sites. The primary lure appears to be a 'practice test with answers'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • 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.
  • 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.
  • 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://dafemum.ru/strik?utm_term=sat+practice+test+7+pdf+with+answers In PDF document text
    • https://cdn.sqhk.co/kepozote/iawheAE/jufugudokaratawonin.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413012/normal_605c58d19b565.pdfIn PDF document text
    • https://cdn.sqhk.co/tetaxekumipi/2FzBjaT/dojumizor.pdfIn PDF document text
    • https://cdn.sqhk.co/pimupigedu/Puihic7/87283164998.pdfIn PDF document text
    • https://deparabijafepoj.weebly.com/uploads/1/3/4/0/134040416/9336429.pdfIn PDF document text
    • https://mowasevibipogo.weebly.com/uploads/1/3/1/3/131379904/mikupomekale-gewebemad.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389571/normal_601a71b084b2a.pdfIn PDF document text
    • https://cdn.sqhk.co/wugunifikezu/Nbchc2S/how_to_fix_windows_defender_update_error.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450509/normal_60095d620b544.pdfIn PDF document text
    • https://jabizujosewej.weebly.com/uploads/1/3/4/5/134584717/xonidopafitiwewob.pdfIn PDF document text
    • https://takimibovejexi.weebly.com/uploads/1/3/4/5/134512521/rifasisoxul.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374835/normal_6060846740c97.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://4b0cdf75-2e42-4830-99f1-bbdbaec3f661.filesusr.com/ugd/891219_d46084790822471fa9702e96ed0d579d.pdf?index=trueIn PDF document text
    • https://d23eb412-52e1-45ef-a32a-0c032022daee.filesusr.com/ugd/03485a_4e59983251a443ea8774c9d52a691436.pdf?index=trueIn PDF document text
    • https://9f1be152-2ea1-4306-981d-bfff62ad382d.filesusr.com/ugd/08fb22_e92cbc689d364a0ea91bfdb0bfe4f2b4.pdf?index=trueIn PDF document text
    • https://f0d491a7-7d72-4eea-bbd3-72ad31f48a9a.filesusr.com/ugd/1acdab_de3a9432c87b486d8be6f471cdda1201.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/joterige/5803998407.pdfIn PDF document text
    • https://e46eb8ae-11b5-47af-91b5-79e2db369635.filesusr.com/ugd/f84671_a99b7cac0df145d3afb2d4fd44e57feb.pdf?index=trueIn PDF document text
    • https://1c684d3d-b1aa-4d58-8f8e-408f9cf37fac.filesusr.com/ugd/64d889_e8e7031c389e4d448473fa5965838a52.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/lofese/saminosajitibanogujexi.pdfIn PDF document text
    • https://s3.amazonaws.com/jawusawar/kukaxoxevo.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f175.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF175 5488 bytes
SHA-256: d603ddeaf327b340a9cfe5ee20327ac1c189ea4a697369caf6acb4c4079abb64
font_01_sfnt_off00010436.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10436 10932 bytes
SHA-256: 407ba25d9d6c13f78b2c384e4a5b415f448ee1f27ad432b36e9d4d16bc40ec23