Malicious PDF — malware analysis report

Static analysis result for SHA-256 cba4fa022e5aa557…

MALICIOUS

PDF

82.8 KB Created: 2021-04-22 17:51:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: e676b01323a303f3e5e097c43fee2403 SHA-1: 06b2708645d4426311ae2d8969033f5cec121554 SHA-256: cba4fa022e5aa557ae47851e94c3136b0a2d87a44423b5e1446caec42c58c15e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The presence of numerous external URIs, many on disposable domains, suggests a link farm or phishing operation. Although no scripts were explicitly extracted, the PDF structure and the nature of the URLs point towards a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • 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://natsihwa.org.au/sites/default/files/webform/46250275999.pdf In PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/nisegat.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/palepipob.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/21691652676.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/tasuwagorefovufozibojer.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/13471650610.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/suvexaxobufakup.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/zozagosetimof.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/sudelo.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/12938533755.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/nolukaronedibikix.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/garuwofewitenobakufenewi.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/zajufofagobixipisuna.pdfIn PDF document text
    • https://www.visitsavannah.com/sites/default/files/webform/59391310887.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=preterite+vs+imperfect+quiz+spanishPDF link annotation
    • https://gradfutures.princeton.edu/system/files/webform/buviboxakutovovujigobimis.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/vogifowisawab.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/mizol.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://www.gnu.org/licenses/gpl.htmlIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e820.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE820 5232 bytes
SHA-256: 291090ca384648e6be463c2f95b670a08dda773b1a49d9b36aaef4b633e96da4
font_01_sfnt_off0000f9bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9BF 6068 bytes
SHA-256: 7a02da73c5ff24218d04b188db7d31ceb9303d5dedd43b645f18a615a19d9b6a
font_02_sfnt_off00010970.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10970 11688 bytes
SHA-256: 5698a11a69d1c562d1613517da7df9a0439326a28d1a502c0e3f41568ec56dd4
font_03_sfnt_off00012f98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F98 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f

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