Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2c35a809d21bf99…

MALICIOUS

PDF

75.0 KB Created: 2021-04-03 04:59:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 6591dc338bb30f512ee1986b8be5fc41 SHA-1: 3dec915c857e320fa182af7f3bab224cbdce93c8 SHA-256: b2c35a809d21bf99a1fff3187833ad64b8af66a895c64b22cbc9881a544e96c1
222 Risk Score

Malware Insights

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

The PDF contains numerous links, with one identified as a known malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document body, though heavily obfuscated, suggests a lure related to educational materials, aiming to trick users into clicking the malicious URL.

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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://yafferge.ru/strik?utm_term=grammar+5+pupil+book+jolly+phonics In PDF document text
    • https://cdn-cms.f-static.net/uploads/4403684/normal_604ae98896fc0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501965/normal_6048beb1f0e4d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369919/normal_602bebdf0885a.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/povelenavuviw/oracle_10g_sql_pl_sql_sqlplus_download.pdfIn PDF document text
    • https://s3.amazonaws.com/dovulavavo/differential_equations__linear_algebra_second_edition_by_farlow_et._al.pdfIn PDF document text
    • https://s3.amazonaws.com/wefemabeni/45054472305.pdfIn PDF document text
    • https://s3.amazonaws.com/fovezewi/how_to_change_tape_in_dymo_letratag.pdfIn PDF document text
    • https://s3.amazonaws.com/purawuma/medical_microbiology_books_free.pdfIn PDF document text
    • https://s3.amazonaws.com/zuxime/3534674029.pdfIn PDF document text
    • https://s3.amazonaws.com/jemazejodep/bisection_method.pdfIn PDF document text
    • https://s3.amazonaws.com/gasodamuza/bhangarh_history.pdfIn PDF document text
    • https://s3.amazonaws.com/duzexefemosaxe/launch_jeff_walker_espaol.pdfIn PDF document text
    • https://s3.amazonaws.com/xapidajovaji/fodakavuka.pdfIn PDF document text
    • https://6ec3981f-6443-463b-a164-91fc69f101d9.filesusr.com/ugd/7603ae_017ae5f53d0f402ca01a4e1e26c5b730.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fezenur/tevoruz.pdfIn PDF document text
    • https://ce3a146a-d504-4efb-981c-4593fb85d965.filesusr.com/ugd/5b5da7_77bca9624bba4fb99764cc6035592604.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kabisebax/itunes_64_bit_windows_8.pdfIn PDF document text
    • https://s3.amazonaws.com/vuforewebub/taropulujukuteduk.pdfIn PDF document text
    • https://s3.amazonaws.com/jazofi/19108615132.pdfIn PDF document text
    • https://s3.amazonaws.com/nupotukig/app_that_gives_math_book_answers.pdfIn PDF document text
    • https://s3.amazonaws.com/donukadizolin/febafizuladuvaronanogapug.pdfIn PDF document text
    • https://2c8134a4-d865-4da1-8961-c755d7242105.filesusr.com/ugd/6dcf04_94786f926bf54f84b689bd35529005f6.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_off0000e550.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE550 5708 bytes
SHA-256: 8fabcccdf45cd05d3af771131137af761a47ad9cd316ab821b34ec063614e970
font_01_sfnt_off0000f89c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF89C 11092 bytes
SHA-256: e3ed185045f0064477b2e837d374b73c4929bb507a84edd26776e93d68be52ac