Malicious PDF — malware analysis report

Static analysis result for SHA-256 c53e07e5542ce3b6…

MALICIOUS

PDF

82.7 KB Created: 2021-08-29 05:07:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f73b2f8b6787c44f6a9727e82319e867 SHA-1: aba92a8cb2330fc4061ab5230b2d65ac11acf881 SHA-256: c53e07e5542ce3b6156f95a4acf97eb1059147effdd92327d805237f056bffdc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF document was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were directly extracted, the nature of the link farm and the PDF's structure suggest it may exploit PDF vulnerabilities or embed JavaScript to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/qpr7oer2igp7oa9dpg322babu7/72968217897.pdf
    • http://hugslock.com/app/webroot/img/files/mamulupirisososuwogigivuj.pdf
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/b1d6643582922a4edb8a912a7920ab4d/daxefefijapowafe.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607e4be435837---tufutimorugim.pdf
    • http://alkanboya.com/files/file///larizajoxag.pdf
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ce28c6e16---jemavawebedefijotaposaku.pdf
    • http://ferrogep99.hu/static/media/file/zuxudosiv.pdf
    • https://angkortaxiservice.com/userfiles/file/47838150278.pdf
    • https://martabaktelor.com/contents//files/36067028173.pdf
    • http://xn--k1akb4c.xn--p1ai/userfiles/file/zozudolukodekavarik.pdf
    • http://finproekt-msk.ru/userfiles/file/sozazugewojijama.pdf
    • https://csn-alliance.com/data/files/52328490942.pdf
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/gmnu6no7e7u7i2kj4oql5i654b/46322744172.pdf
    • http://word.mn/uploads/assets/29345512076.pdf
    • http://inistor.com/ufiles/files/47849074273.pdf
    • http://baugeraeteverleih.de/benutzerdateien/74093880101.pdf
    • http://www.temaricerca.com/entry2013new/admindia/ckfinder/userfiles/files/68319795843.pdf
    • https://roweryelectra.eu/app/webroot/uploads/file/16199688193521.pdf
    • https://ego-sofa.tw/uploads//files/202108040651443494.pdf
    • https://diaochue.vn/userfiles/file/fovepelaxagupiva.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16079197c3f6c5---13928824335.pdf
    • http://chiangmaicharmingtravel.com/ckfinder/userfiles/files/tibekomulunefosibufa.pdf
    • https://htchninc.com/d/files/lutagaxefud.pdf
    • http://hillsdalehorseboarding.com/ckfinder/userfiles/files/59633335415.pdf
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/h5tvcokgdlf9plgv6408ukkimn/48489216418.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=i+lost+weight+by+walking+every+day
    • 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_off0000dccb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCCB 16792 bytes
font_01_sfnt_off0000f4dd.bin
24ed8ea720068a9c029f68e3decc743ac03b4c7e16c1a422bad2a14b3f1ab460
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4DD 17724 bytes
font_02_sfnt_off0001228f.bin
e3d4567966daa0d82e4cb751f8ba978c73f1f74d4abdb58bd387a9d8abdbb292
pdf-font-stream PDF embedded font (sfnt) at offset 0x1228F 10976 bytes