Malicious PDF — malware analysis report

Static analysis result for SHA-256 31515e106c5498f7…

MALICIOUS

PDF

64.9 KB Created: 2021-02-22 13:42:11 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 88b26471d55ec8fb97de6767cff9d850 SHA-1: 222a9f6bf2fb609bab54ded0f34039ce4a91d800 SHA-256: 31515e106c5498f7c9cacf46a60974ade300aa6413c26d19b70392c8008ed9f7
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 of which are to PDF files, suggesting a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and numerous external URLs point towards a phishing or malicious content delivery mechanism, likely initiated via 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://leonvi.ru/wix?keyword=wh+worksheet+tes
    • https://bifitulodagox.weebly.com/uploads/1/3/6/0/136081839/3589332.pdf
    • https://cdn-cms.f-static.net/uploads/4385021/normal_60199da851d2e.pdf
    • https://sukodijam.weebly.com/uploads/1/3/4/5/134516983/3763544.pdf
    • http://vigastlens.xyz/sijabepefasirerlix5.pdf
    • https://wijirejilape.weebly.com/uploads/1/3/2/8/132816202/jujepidide_rinema_tumadixafifixan_lulixelero.pdf
    • https://static.s123-cdn-static.com/uploads/4495526/normal_5ff69c93e7b5e.pdf
    • https://cdn.sqhk.co/dovoxukeni/gchhjc3/temovoxizazivenupusenam.pdf
    • https://cdn.sqhk.co/muwitajo/zDjg2ha/dwayne_johnson_hd_wallpaper_for_desktop.pdf
    • https://cdn.sqhk.co/nevupediwix/AVGhi7A/translate_english_to_russian_cyrillic.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/lekizopiloref/capricho_arabe_violin.pdf
    • http://jixonolalosixew.rf.gd/duzap.pdf
    • https://s3.amazonaws.com/xupimaral/99292318854.pdf
    • https://s3.amazonaws.com/devuxuzejozam/lizakafedizapen.pdf
    • https://s3.amazonaws.com/fefurorobumi/33886718886.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_off0000c4ac.bin
949404c852208cec47c72dafac0b7ab88db2e369560b7a0a8ed461da0046bc83
pdf-font-stream PDF embedded font (sfnt) at offset 0xC4AC 4700 bytes
font_01_sfnt_off0000d4ba.bin
eec802cfa8dbc14f1b01f3dad44f1471a9107acc69889839c55525aea99ee4d7
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4BA 9932 bytes