Malicious PDF — malware analysis report

Static analysis result for SHA-256 278923d610b4f659…

MALICIOUS

PDF

88.2 KB Created: 2021-08-10 00:03:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c0870102d6c5385a3bdc98bb79638ba4 SHA-1: d8d25b7b7f9cb389c46bd75287f5b45c3a07e657 SHA-256: 278923d610b4f6592cb0460770d88f46a6310b12fb57cc50450f54f5e8348ef2
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users. The presence of a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites, suggests an attempt to obscure the final destination and potentially distribute further malicious content or conduct phishing. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a non-clustered link farm on disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1609069993b5a5---tugasage.pdf In PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/160932a0c36908---nojebafalidaxurumexum.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/silibar.pdfIn PDF document text
    • https://mednet.mk/public_html/upload/userfiles/file/65195802616.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/16105a23de64ba---sizibugajikojodobuxi.pdfIn PDF document text
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/dknd0qf04nlq3ep1k2vv9a73n5/56231816214.pdfIn PDF document text
    • https://info-jimukyoku.jp/lot/upload/files/ridapopokezogawog.pdfIn PDF document text
    • http://lindendirect.com/ckfinder/userfiles/files/delegulawujuxorepukaxe.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/btdlevkmjpa24m7ibg1v9be7f3/nakurunejidetuzeluzunixe.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160baf558491ab---10594001118.pdfIn PDF document text
    • http://sllight.ru/design/img/upload/file/14275856055.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/3d1c26369de45562622f61b591faa6d5/59188316914.pdfIn PDF document text
    • http://plusk-car.com/js/upload/files/suvozesijagimuki.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a16b5271dc7---84606277595.pdfIn PDF document text
    • http://trevelsi.ru/ckfinder/userfiles/files/saxivebapudexagoji.pdfIn PDF document text
    • http://www.rannatennis.ee/data/upfiles/files/fubusamipanogizekasodo.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16076851e14bbe---dumure.pdfIn PDF document text
    • http://nsdadventist.org/FCKData/file/47147173484.pdfIn PDF document text
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/5b08937d54fe3b28a7dbc2941aa03410/65755551857.pdfIn PDF document text
    • https://lescourailleurs.com/upload/editor/file/robekutegakunurufazidewol.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/160e8cb71db604---vinamunuk.pdfIn PDF document text
    • https://ascinfratech.com/clientprojects/trading/file/51708091280.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089e57c87d6b---44689091535.pdfIn PDF document text
    • http://remont-etalon.ru/upload/files/fubuladonizimuwob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=examen+diagnostico+preescolar+2+pdfPDF 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_off0000e880.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE880 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010092.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10092 21060 bytes
SHA-256: 59bef92bae84eb2397ed2cc2f5d8a4524a67661c226b394d04b05bec580d1bf9
font_02_sfnt_off00013697.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13697 11168 bytes
SHA-256: d9fab37611d3c3eca2e898391d4b85054e0df6860e4aaca7a4e031ca928e0668