Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c4b39440e29e5a2…

MALICIOUS

PDF

79.5 KB Created: 2021-09-13 18:16:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 045183a69ec25974ac46512402c28f0e SHA-1: 1ac4183b56a53ea86e93745b0f45e51c7add78a5 SHA-256: 1c4b39440e29e5a27c51cd39e09606f17d3692003f5536dcd580fd12fdd8efcc
156 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. It contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites used for hosting malicious files. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for link farms, suggesting an attempt to obscure the true malicious destination. The presence of external URIs and link farms strongly suggests the document's purpose is to redirect users to malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://synerhu.ru/uplcv?utm_term=rooter+app+coin+hack PDF link annotation
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/ec35558135eb340f0ab0ff26996c49ed/buvapozenamaxefifukekipax.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139b84dd5664---rowinikiv.pdfIn PDF document text
    • https://gencatakan.com/upload/file/81473442918.pdfIn PDF document text
    • http://thessalonikiflights.com/files/files/58195232437.pdfIn PDF document text
    • https://aynispirit.nl/userfiles/file/wulivigubivuruviluwo.pdfIn PDF document text
    • http://www.ortodonciaelisafarache.com/ckfinder/userfiles/files/zupibibinowowek.pdfIn PDF document text
    • https://avistravel.activsport.ro/userfiles/file/39498876338.pdfIn PDF document text
    • http://edilgroupdigiovanni.it/userfiles/files/80205170666.pdfIn PDF document text
    • http://beautifulmoda.com/userfiles/files/21021751048.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/316d2fad9885cb72d710ded34708734a/binoxe.pdfIn PDF document text
    • http://www.ktgroup.co.uk/ckfinder/userfiles/files/defejozamixoleseko.pdfIn PDF document text
    • http://artkulinaria.pl/sites/default/files/file/65322700937.pdfIn PDF document text
    • http://euredit-editions.com/userfiles/file/17715942029.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613a747d18ee8---22135172153.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/guzip.pdfIn PDF document text
    • http://www.niziointerior.pl/upload/file/57024053180.pdfIn PDF document text
    • http://www.medic-pneumolog.ro/fisiere/file/xelaxikisinelutomamaxiju.pdfIn PDF document text
    • http://taigesw.com/upload/files/22750899289.pdfIn PDF document text
    • http://energyexcess.com/userfiles/file/nanemelategelanapabax.pdfIn PDF document text
    • https://rosycaffe.com/file/lapafaganobosawulidisaxud.pdfIn PDF document text
    • http://libertyquad72.fr/userfiles/file/putekufoxibilutawulu.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/ziruzirunuzuzi.pdfIn PDF document text
    • http://infinijewelry.com/userfiles/file/34053598825.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_off0000d381.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD381 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB98 10396 bytes
SHA-256: 2c1297c0a6187a6a9c625d0355be74aa833e90f746e0f183c30528ad4b75c4c2
font_02_sfnt_off00010306.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10306 17784 bytes
SHA-256: 04eaee07ecef503aac8865d1097590c772d1d82bdf3a8d8f894b7f03377a4115