Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3831820ddf689e1…

MALICIOUS

PDF

72.2 KB Created: 2021-09-25 11:52:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e69f6ec3301255a1b57bea1080f26df2 SHA-1: da24e2d2050010c86f4331785ecf9dbb3f4a9c00 SHA-256: f3831820ddf689e1081b592fdcd5f61d3adf36e3cdacb9b88d81c90c1219af52
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The heuristics indicate it functions as a link farm, directing users to numerous external URLs, some of which are hosted on disposable domains. While no scripts were explicitly extracted, the presence of embedded URLs and the link farm nature strongly suggest an intent to redirect users to malicious sites for further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://drcleancenter.com/uploads/files/202109191552255145.pdf
    • http://jagdrevier.hu/upload/images/file/68090952065.pdf
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/20494008b857baf3f41b549d43e316ac/5169741338.pdf
    • http://oilmachineydy.com/d/files/fopevuxotubemazubutol.pdf
    • https://mkserwis.pl/userfiles/file/4481346571.pdf
    • http://kasargod.net/uploads/file/64240410371.pdf
    • https://soenen-pneus.com/upload/file/18012615507.pdf
    • https://misbahelmudii.org/ckfinder/userfiles/files/2280839513.pdf
    • http://nguyenxuanhuong.com/upload/files/51700255465.pdf
    • http://massimomoroni.it/userfiles/files/tamelodijawodaxabavifi.pdf
    • http://lynxitservices.com/ckfinder/userfiles/files/45593094128.pdf
    • http://kmjmt.com/news/upload/file/210910203536017654ljo7nt.pdf
    • http://unternehmensberatung-hegenbarth.com/userfiles/file/37275870913.pdf
    • https://edu-mate.kr/_UploadFile/Images/file/45983410199.pdf
    • http://caramelitos.sk/files/67283440069.pdf
    • http://hytechcommunications.com/userfiles/file/79951956041.pdf
    • http://natur-pet.cz/webpagebuilder/ckfinder/userfiles/files/71124411695.pdf
    • http://kammed.com/userfiles/file/35243983578.pdf
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146d529ed232---91790904862.pdf
    • http://niktid.ru/userfiles/file/11241810457.pdf
    • http://axi-hohenstein.de/userfiles/file/47854271540.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=latest+bollywood+web+series+free+download
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b1ec.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB1EC 16792 bytes
font_01_sfnt_off0000c9fe.bin
958d8f7b3a9182efa27d5d885eb67ae27df7e8f9a4781a009a7accc4b3e570b6
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9FE 18736 bytes
font_02_sfnt_off0000fa88.bin
2828592b765f9e1f4dfc068f8845f6b38b3ecf063385d21302e6b5ee9cd9692b
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA88 10644 bytes