Malicious PDF — malware analysis report

Static analysis result for SHA-256 0caff41ee29f020b…

MALICIOUS

PDF

85.0 KB Created: 2021-09-16 16:18:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 829b1f8286a221de10ab52b9a86262c5 SHA-1: 81ee7332519b735abb405ae2f2d269ec0968256f SHA-256: 0caff41ee29f020b780162bd3f7d1bd5c6563161304bed709fd1e67f1cee67c4
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress sites and disposable hosting. The document body is heavily obfuscated, preventing analysis of its direct content, but the presence of external links and the overall detection profile strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://crewmak.ru/uplcv?utm_term=buscar+fotos+borradas+android
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161433d3517652---perojafakozusebulo.pdf
    • http://angelojrobles.com/admin_initial_test/userfiles/file/xavezularupolafapum.pdf
    • http://zhjpharm.com/upload/files/81407246392.pdf
    • http://meubelenindex.nl/images/uploads/19405027188.pdf
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/54656d8f04f1985c9e14d9df6fcda379/tikewusifetasabagikorozu.pdf
    • http://abwva.com/uploads/files/20977230488.pdf
    • https://polresseluma.com/assets/ckfinder/core/connector/php/uploads/files/25425349003.pdf
    • http://caratow.eu/userfiles/file/82069968264.pdf
    • http://kbcsisa.com/upload/fckeditor/file/bolopagu.pdf
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/6bf81e3432b0f97783e4a69db8896805/48107545339.pdf
    • http://yugang360.com/upload_fck/file/2021-9-4/20210904163838178107.pdf
    • http://robwalker.net/fckupload/file/wegijilakij.pdf
    • https://baoholaodong24.baohohoanglong.com/userfiles/file/jakaz.pdf
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/40728852203.pdf
    • http://idominjazz.com/fckeditor/userfiles/image/pikosesazomaxovixaguzafox.pdf
    • http://www.biogreeno.com/cms/ckfinder/userfiles/files/muduripejudedeno.pdf
    • https://big-affaires.com/img/pics/files/metibuvu.pdf
    • http://carzip.biz/files/uploads/files/17688038057.pdf
    • http://northcity.rs/slike/files/1355974063.pdf
    • http://printific.com/images/contentimages/files/57428515760.pdf
    • https://mygrind.ie/userfiles/file/sepugofowixufeburiwiku.pdf
    • http://www.bongbansaigon.com/uploads/files/29643676995.pdf
    • http://starroadchina.com/userfiles/file/razikuvisososajizisu.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://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_off0000e440.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE440 16792 bytes
font_01_sfnt_off0000fc52.bin
b954ac4552be4984c0503fb7e6660f57b507d7a376cfc55a9d8b11093fcb4134
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC52 19204 bytes
font_02_sfnt_off00012da8.bin
95a8069c0bf153e632733c59f77a212d9d30f8cf102c85563589fa6691e93472
pdf-font-stream PDF embedded font (sfnt) at offset 0x12DA8 10584 bytes