Malicious PDF — malware analysis report

Static analysis result for SHA-256 834d9e5e777e7455…

MALICIOUS

PDF

76.8 KB Created: 2021-04-11 00:01:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: c454a645ee57524b9a78879e0752a7af SHA-1: 6a62b67304019d259540e9b14d3007111fe2d363 SHA-256: 834d9e5e777e745559a8ca020d982a328f583aafd9c54418fec9b249ae031118
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of external links, many pointing to disposable hosting services, suggesting a link farm or SEO spam operation. The primary URL, 'https://bologen.ru/strik?utm_term=how+to+become+a+pet+nutritionist', is presented as a lure for information about pet nutrition. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing unwanted content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://bologen.ru/strik?utm_term=how+to+become+a+pet+nutritionist PDF link annotation
    • https://viriparerari.weebly.com/uploads/1/3/5/9/135978168/4376282.pdfIn PDF document text
    • https://japugaze.weebly.com/uploads/1/3/5/2/135295186/jubolulusimazu_mavukagolu.pdfIn PDF document text
    • https://togezajotutev.weebly.com/uploads/1/3/0/8/130874352/jutudomupogurozun.pdfIn PDF document text
    • https://dibekojiworibo.weebly.com/uploads/1/3/1/6/131637919/xovejalamoxo.pdfIn PDF document text
    • https://cdn.sqhk.co/xipugonor/0sigbhc/wejedusim.pdfIn PDF document text
    • https://dofafurubes.weebly.com/uploads/1/3/4/7/134762343/b2927d7a27315.pdfIn PDF document text
    • https://cdn.sqhk.co/jonimaze/iThdTgd/the_sims_freeplay_hack_tool_free_download.pdfIn PDF document text
    • https://cdn.sqhk.co/jixuvepabu/Hgdhfgd/79440284233.pdfIn PDF document text
    • https://wosuletoxo.weebly.com/uploads/1/3/0/7/130739711/panomibabaxadik.pdfIn PDF document text
    • https://cdn.sqhk.co/mukibusu/cSgi3ij/xedisexoxofuzekajifunejov.pdfIn PDF document text
    • https://latuxuxapeja.weebly.com/uploads/1/3/0/7/130739017/tiduladi_navase.pdfIn PDF document text
    • https://cdn.sqhk.co/pubusudes/icjgjhL/42750013608.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://f37c3615-20b0-4e70-b1e7-2acf34113780.filesusr.com/ugd/1e533a_deca27f69eaa49daafbf2bf90aeca02b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/59bfbd5e-3ab6-48e1-a669-73a6d31cda80/math_workbook_grade_1_free_download.pdfIn PDF document text
    • http://wikizunawun.rf.gd/ejemplo_diagnostico_organizacional.pdfIn PDF document text
    • https://3d7c42e8-cad9-4196-8f3c-0f210fd97588.filesusr.com/ugd/1b7c00_a58a2c0b6f164e12b51319b66a488b39.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3bb6ee38-9368-43ac-9ef4-836bce1a13f0/how_to_manage_disruptive_behavior.pdfIn PDF document text
    • http://godubaxedija.rf.gd/baker_s_crust_menu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b76062c4-8135-4f4e-9b40-4ad943de5640/96591947438.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c5a3698b-02a8-4081-970d-b812f0514d7b/tofazefixamag.pdfIn PDF document text
    • http://jarawujutuva.epizy.com/39498621507.pdfIn PDF document text
    • http://fuzazoxavuvuw.rf.gd/how_to_measure_wheel_size_for_bike_computer.pdfIn PDF document text
    • https://89511c73-251b-4bee-a1a5-5f4bd4863124.filesusr.com/ugd/f24cb8_f5b948757a49465183e0b11a33d1412a.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7ec45fc3-ad6e-4133-bd3f-0f29af7da42d/romekuxobavaxar.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_off0000ef7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF7D 5240 bytes
SHA-256: 53c24f137fcb60344214577d5f4c1c2a5398ed4ff8d9a694a908f3732356bbe7
font_01_sfnt_off00010140.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10140 10752 bytes
SHA-256: d3c5f9e3681ef7ff9f9670e82007eacf1e91b2cd64df69ba03c90649618c854f