Malicious PDF — malware analysis report

Static analysis result for SHA-256 b77e187b1c0f8b13…

MALICIOUS

PDF

81.1 KB Created: 2021-09-11 22:28:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 1077046a0eb53bf25549453db1cd0efc SHA-1: 0d64d797b66bdffff2500102c4064f453beefb0c SHA-256: b77e187b1c0f8b135644709b871ac4fcf4cd99ff61a24b9fba9257cacab9ec80
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains a large number of external URLs, suggesting it functions as a link farm to distribute phishing content or download further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically points to this behavior, leveraging disposable hosting and redirectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://smidgel.ru/uplcv?utm_term=viro+4g+smartphone+review PDF link annotation
    • https://norservis.com/files/files/24752568246.pdfIn PDF document text
    • http://thienanglass.vn/upload/files/32713613180.pdfIn PDF document text
    • http://canhtoanland.com/upload/files/4963353245.pdfIn PDF document text
    • https://perkunasstudio.com/uploads/files/202109082203237450.pdfIn PDF document text
    • https://tresonance.org/uploadfiles/buxetutuvibigakonufawat.pdfIn PDF document text
    • http://xindeshiye.com/uploadfile/file///2021090200574718.pdfIn PDF document text
    • http://gpszone.hu/upload/userfiles/file/3499166880.pdfIn PDF document text
    • http://gongotour.com/FileData/ckfinder/files/20210909_75864FD11C11CA57.pdfIn PDF document text
    • https://www.kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/xixan.pdfIn PDF document text
    • http://odumakus.com/uploads/files/lixozameda.pdfIn PDF document text
    • http://maxgear.cz/webpagebuilder/ckfinder/userfiles/files/fopomerazarutuw.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/ea0a54904858fc73d214a3afced0b449/bajuxisenelikaxegaf.pdfIn PDF document text
    • http://foto-recepty.sk/images/fotky/kuzudunose.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/wemudeveturalovonepe.pdfIn PDF document text
    • https://polytex.de/sites/default/files/29347247317.pdfIn PDF document text
    • https://mollis.rs/files/xejusafovu.pdfIn PDF document text
    • http://kbcsisa.com/upload/fckeditor/file/17140536695.pdfIn PDF document text
    • http://dienlanhhuubinh.com/upload/files/69069255138.pdfIn PDF document text
    • https://digireg.cn/upload/2555117835.pdfIn PDF document text
    • https://habrit.tw/ckfinder/userfiles/files/kugomovarerolu.pdfIn PDF document text
    • http://lifeline-sports.com/files/file/fijofon.pdfIn PDF document text
    • http://kapsalonvogue.nl/files/file/44058592263.pdfIn PDF document text
    • http://aptekadc.pl/userfiles/userfile/79263611989.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/161313b7e78e84---84559122593.pdfIn PDF document text
    • http://csc0512.com/userfiles/file/20210904101543_r7sgxp.pdfIn PDF document text
    • http://abpjseah.news-read.com/upload/files/62089931280.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_off0000d7cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7CB 17776 bytes
SHA-256: d6cd1734cb25f26496829bf5749958bb237b33c02aa9232faeac591514621d3f
font_01_sfnt_off000105b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105B6 10852 bytes
SHA-256: af7f7d4db55cfab74ca7e3142292f86ad3b1414c39c1b4fdfbf3575ea58402c6
font_02_sfnt_off00011ec2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EC2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1