Malicious PDF — malware analysis report

Static analysis result for SHA-256 71b57000c879ae38…

MALICIOUS

PDF

73.6 KB Created: 2021-09-13 03:01:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e37711b20b4c096f2cbc625f654b64c7 SHA-1: acee7d2bf1610a9ad49234eb528d64c7d9a1ec69 SHA-256: 71b57000c879ae38ffa6b95d90f73f836b238b9767f13d9d5efcd1cd905f4c2d
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous links to external URLs, many of which are hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript and link farm behavior suggest an attempt to lure the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://coretry.ru/uplcv?utm_term=united+states+of+america+republic PDF link annotation
    • http://perechen-jurnalov.ru/js/ckfinder/userfiles/files/mogojadij.pdfIn PDF document text
    • http://taemyung.com/data/upload/file/20939368410.pdfIn PDF document text
    • http://www.adarshvidhyasankul.org/userfilesfile/pakojusepulixazesowijit.pdfIn PDF document text
    • http://gianniarnaudo.com/userfiles/files/gosovutoworimajo.pdfIn PDF document text
    • https://ddtoyz.com/ckfinder/userfiles/files/71422392193.pdfIn PDF document text
    • http://www.huescalamagiaenfotos.com/userfiles/files/1900450839.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3513d15d50f85755ed1e731a59bd2f37/vatojokosu.pdfIn PDF document text
    • https://www.wemservice.com/ckfinder/userfiles/files/nikujitepuninuj.pdfIn PDF document text
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/34493136045.pdfIn PDF document text
    • http://xn--h49al33a2zdp0eo1x.com/DATA/file/20210904052435.pdfIn PDF document text
    • http://tagsu.com/attachments/fckattachments/file/podopuro.pdfIn PDF document text
    • https://akconta.com/uploads/files/31985245780.pdfIn PDF document text
    • http://ride-on-earth.com/images/blog/file/namozejetisav.pdfIn PDF document text
    • http://pate4me.com/userfiles/file/16907334394.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394ba93250f---82738953970.pdfIn PDF document text
    • http://abworder.com/uploads/files/sijudepaxofola.pdfIn PDF document text
    • http://dulwichtaxi.com/survey/userfiles/files/lamir.pdfIn PDF document text
    • http://2018.letnifestiwal.pl/ckfinder/userfiles/files/68982690107.pdfIn PDF document text
    • http://flashdisplay.net/UploadFiles/FCKeditor/20210909043316.pdfIn PDF document text
    • http://nedvizhimost-v-sharm-el-sheikhe.ru/uploads/files/6411738415.pdfIn PDF document text
    • http://khonggianmang.com/upload/files/28824170396.pdfIn PDF document text
    • http://lso-msm.com/userfiles/file/82611118856.pdfIn PDF document text
    • https://m-isc.com/userfiles/file/sitidugu.pdfIn PDF document text
    • http://nextlab-semi.com/files/fckeditor/file/36982250529.pdfIn PDF document text
    • http://sushi-belovo.ru/files/8030681474.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bcb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCB5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d4cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4CC 11028 bytes
SHA-256: f8cf203e56a0ae68f04240e9a59633cc083c5fa0b665ab1d474abf2941dbace3
font_02_sfnt_off0000ee30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE30 16588 bytes
SHA-256: 76dc24f4201309d2cdb09cac1d206082f6a4c33c7633d8578c36080617b2b69e