Malicious PDF — malware analysis report

Static analysis result for SHA-256 83570e433d7138fc…

MALICIOUS

PDF

77.8 KB Created: 2021-03-17 01:20:12 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 550dba65320162409271d9506c46e371 SHA-1: 2c07c79fb7df3c278392a9db6566cc6fbdf27716 SHA-256: 83570e433d7138fcd9e8e799c88c2b78240974db8777a6ad97ef6aebfa943f2f
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to Weebly and other free hosting services, suggesting an SEO spam or phishing campaign. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of techniques used to redirect users to malicious sites.

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-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pelibifir.ru/award?keyword=beginning+esl+worksheets+pdf
    • https://zokaguwozan.weebly.com/uploads/1/3/0/7/130738936/1699299.pdf
    • https://fiwisito.weebly.com/uploads/1/3/4/7/134715438/5a39cd3e0.pdf
    • https://kiburosipaso.weebly.com/uploads/1/3/4/6/134601321/petutokumuve.pdf
    • http://pixidilivutep.medianewsonline.com/how_to_charge_trolling_motor_battery_with_solar_panel.pdf
    • https://static.s123-cdn-static.com/uploads/4370090/normal_5fc67f1d2f315.pdf
    • https://static.s123-cdn-static.com/uploads/4385038/normal_5fe2d99761236.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/tibitexil/sasakirawujipadijej.pdf
    • http://vilepobafomunow.atwebpages.com/xubegasoxabuduped.pdf
    • http://megigezorozo.atwebpages.com/what_are_the_parts_of_narrative_writing.pdf
    • https://s3.amazonaws.com/fibesezati/99035380462.pdf
    • https://s3.amazonaws.com/kezemiradigu/76076193236.pdf
    • https://s3.amazonaws.com/fupanabivote/basketball_game_images.pdf
    • https://s3.amazonaws.com/gelawiweza/bhagavath_geetha_in_malayalam.pdf
    • https://s3.amazonaws.com/xujitezu/98676845943.pdf
    • https://s3.amazonaws.com/kufazete/38735170966.pdf
    • https://s3.amazonaws.com/zatasipezeg/hungry_shark_evolution_mod_apk_revdl.pdf
    • http://buzumigasox.myartsonline.com/28303803762.pdf
    • https://s3.amazonaws.com/tafogusegabomu/widening_access_scheme_claim_form.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_off0000f32e.bin
7ebad59609ff82a28fd89c8b910b1a9a130eabb36d83c30cc97f7f381e846e41
pdf-font-stream PDF embedded font (sfnt) at offset 0xF32E 5300 bytes
font_01_sfnt_off0001054b.bin
ab19a087333cd347476e50e5db1f98a31e85b87e9ef8007dfab42a5eacfa5c71
pdf-font-stream PDF embedded font (sfnt) at offset 0x1054B 10852 bytes