Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b35d467b58590c0…

MALICIOUS

PDF

77.7 KB Created: 2021-09-14 07:38:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: efb9eaa9d58c65aabc234c7b240116c6 SHA-1: 008f6975ff038215cf662d595fb2daafafffd56b SHA-256: 8b35d467b58590c0ed16568b1b7628c015ec3cb4305501ae7af772fc7e6caf3d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. The document contains a large number of embedded URLs, many of which point to other PDF files hosted on various domains, suggesting a link farm or redirection scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating the PDF is designed to host numerous links on disposable hosting. The primary goal appears to be directing users to external sites, potentially for malware distribution or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://autoandtruckrepair.net/nbloom/fckuploads/file/40010703415.pdf In PDF document text
    • http://filipdegreef.be/uploads/files/jituba.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/5f1ba78627d5362e6b09d4f83ef0ba7e/55387690129.pdfIn PDF document text
    • http://nsdadventist.org/FCKData/file/92579176036.pdfIn PDF document text
    • http://patrickstaxi.fr/userfiles/file/ponabase.pdfIn PDF document text
    • http://dothi.info/images/files/70325106040.pdfIn PDF document text
    • https://odontologosmalca.com/images/userfiles/file/87247624163.pdfIn PDF document text
    • http://sirmamedia.com/ckfinder/userfiles/files/72858819982.pdfIn PDF document text
    • http://canshu.dlzj.net/upload/files/20210905175840888384.pdfIn PDF document text
    • https://pasationtravellers.com/root/FCKeditor/file/konexujug.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/naviza.pdfIn PDF document text
    • https://travelworld.ro/userfiles/file/28247484875.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/mutezujenakuvejeva.pdfIn PDF document text
    • http://riviera.az/userfiles/file/930992569.pdfIn PDF document text
    • http://1night2day.com/ckupload/files/pagofopovena.pdfIn PDF document text
    • http://jiuxingchaoshi.com/uploads/file/042102481662.pdfIn PDF document text
    • http://wellgroup.cz/UserFiles/File/vikoxufamewebefideziba.pdfIn PDF document text
    • http://areawifi.com/DESARROLLO/userfiles/files/mobirukuzijezizede.pdfIn PDF document text
    • http://kingbikeonline.com/images/upload/File/9875192848.pdfIn PDF document text
    • http://mtkshop.com/images/uploads/file/84858351125.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/tokeletojilakon.pdfIn PDF document text
    • http://ambulatorioveterinariorigolon.eu/userfiles/files/36472692264.pdfIn PDF document text
    • http://amsasecretariat.fr/userfiles/file/91372232182.pdfIn PDF document text
    • http://tieuhocsongphuong.hoaiduc.edu.vn/ckfinder/userfiles/files/gopumumonigixijubap.pdfIn PDF document text
    • http://sensitiva.fi/UserFiles/File/85970861678.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=truecaller+pro+download+apkPDF link annotation
    • 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_off0000cc9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC9B 17288 bytes
SHA-256: 61db56c33d0e7ac9d696b99741dc8e9fe15900141fce240dda0c4f73a08672ad
font_01_sfnt_off0000f982.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF982 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011199.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11199 10388 bytes
SHA-256: 8da5e83969871561c63189459ce10d126ce61f6ad867e62d6a125f8c94000809