Malicious PDF — malware analysis report

Static analysis result for SHA-256 21d69a3461e1c8c9…

MALICIOUS

PDF

77.8 KB Created: 2021-04-16 01:44:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 6c54f515bf82ea6ffbae8bd59f2b126d SHA-1: a13f82bd3502254d08cf1d1ea1c6e91391d08185 SHA-256: 21d69a3461e1c8c904358658c1428167efa66221d92fdcf8b414670a33bba068
126 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to disposable domains, and is flagged as a link farm. The document body, though heavily obfuscated, contains text related to 'arrow shaft size' and 'wkhtmltopdf', suggesting a lure to external content. The presence of external URIs and the link farm heuristic strongly suggest this PDF is designed to redirect users to potentially malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://maypoin.ru/strik?utm_term=how+to+choose+arrow+shaft+size PDF link annotation
    • http://varistop.site/legolono4ray8.pdfIn PDF document text
    • http://segepivo.22web.org/12_steps_to_recovery_lds.pdfIn PDF document text
    • https://tokoposejod.weebly.com/uploads/1/3/1/3/131380771/796c3bd9.pdfIn PDF document text
    • http://sodamasagu.66ghz.com/56119213986.pdfIn PDF document text
    • http://randname.ru/87980657593xgy4r.pdfIn PDF document text
    • https://punujagenak.weebly.com/uploads/1/3/0/7/130775029/7589745.pdfIn PDF document text
    • http://top-agent.ru/junie_b_jones_dumb_bunny_read_aloudqza8z.pdfIn PDF document text
    • http://bulasige.iblogger.org/84605421449.pdfIn PDF document text
    • http://air-calm2.club/splash_screen_android_library9yzlc.pdfIn PDF document text
    • https://redulexaxoxega.weebly.com/uploads/1/3/0/8/130874010/lozigafizeti_kavofufusamibu.pdfIn PDF document text
    • https://zadevadetolilug.weebly.com/uploads/1/3/5/3/135321342/5944974.pdfIn PDF document text
    • https://jijibaduwa.weebly.com/uploads/1/3/4/4/134495912/7674592.pdfIn PDF document text
    • http://wogigafulokeme.22web.org/wobixivufanabawi.pdfIn PDF document text
    • https://fukudikewug.weebly.com/uploads/1/3/4/6/134686524/6702228.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://jidufatasakameg.epizy.com/do_any_doctors_still_make_house_calls.pdfIn PDF document text
    • https://s3.amazonaws.com/buponuwebi/england_rugby_team_sheet_2019.pdfIn PDF document text
    • http://xazoviwupudowol.rf.gd/48336739352.pdfIn PDF document text
    • http://fasizoj.rf.gd/chicken_pox_adults_guidelines.pdfIn PDF document text
    • http://tononade.rf.gd/53262167652.pdfIn PDF document text
    • https://s3.amazonaws.com/rurosaveruk/briggs_and_stratton_6250_watt_generator_manual.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_off0000f2f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F1 5040 bytes
SHA-256: 7995ccc336539e260b536360eb25e6db0bbad7989805919eaec9adc06cd48f76
font_01_sfnt_off0001042b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1042B 10600 bytes
SHA-256: 70b65a9553eba91edcfd7a52022bfa6b3bafbd87128a2730ba389b77b49d6d13

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