Malicious PDF — malware analysis report

Static analysis result for SHA-256 81459955650398a8…

MALICIOUS

PDF

70.7 KB Created: 2021-03-14 05:25:49 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f7c704c440f9830834f27129aca7afba SHA-1: c91483736e41719de882c89ffae50fc2b9936e32 SHA-256: 81459955650398a88528e4a567f58a8166d73577b574892fab639e95e0d36ef2
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to domains associated with SEO spam or phishing. The heuristic 'PDF_SEO_LINK_FARM' indicates a mass of external links, and the ClamAV detection as 'Pdf.Phishing.Trojan' strongly suggests malicious intent. While no scripts were explicitly extracted, the PDF structure and numerous external URLs point towards a malicious campaign, likely involving spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jacksth.ru/wix?keyword=oxford+guide+to+english+grammar+pdf
    • https://cdn.sqhk.co/gofelaxes/3jLpT1h/crackle_apple_tv_code.pdf
    • https://lijipipixeralof.weebly.com/uploads/1/3/3/9/133999964/132907bf85ab.pdf
    • https://cdn.sqhk.co/mubasetopagu/gaBhjgf/video_maker_free_download_apk.pdf
    • https://cdn.sqhk.co/birugafomafo/6oqjPhb/55608715182.pdf
    • https://dirogine.weebly.com/uploads/1/3/0/7/130775503/fabaf.pdf
    • https://cdn.sqhk.co/sunomedude/gjihid6/78682843823.pdf
    • https://kowagazobavov.weebly.com/uploads/1/3/0/8/130874359/ronabevi_pokoxe.pdf
    • https://cdn.sqhk.co/gexedamej/Fwhak2F/60424314231.pdf
    • https://nalivugubogepa.weebly.com/uploads/1/3/0/9/130969323/169108.pdf
    • https://baduzizexajozej.weebly.com/uploads/1/3/4/6/134653824/moxuvofif.pdf
    • https://cdn.sqhk.co/jevamivuvugi/yUibYAY/pc_creator_pc_building_simulator_wiki.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/pilazi/leccion_1_contextos_quiz_b_answers.pdf
    • https://s3.amazonaws.com/widuxade/sazizox.pdf
    • https://s3.amazonaws.com/zaxefemebidaz/boiling_point_of_acetic_acid.pdf
    • https://s3.amazonaws.com/gorajikunobixi/gekixodizamig.pdf
    • https://s3.amazonaws.com/bipovoromoj/how_to_interpret_t_test_results_example.pdf
    • https://s3.amazonaws.com/xeropizuwe/algebra_1_eoc_math_reference_sheet.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d6b2.bin
f3e9c7272d59aa6a82398889c9e495b66e5c149016ff9a6c1342ee22a5ad8819
pdf-font-stream PDF embedded font (sfnt) at offset 0xD6B2 5548 bytes
font_01_sfnt_off0000e96f.bin
5d0d4e30e12f29c532a3a1739b475ddbffbdde4689bd341f6d5affb1ab6faf93
pdf-font-stream PDF embedded font (sfnt) at offset 0xE96F 10692 bytes