Malicious PDF — malware analysis report

Static analysis result for SHA-256 f675d3a86907957c…

MALICIOUS

PDF

77.5 KB Created: 2021-10-08 02:25:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 800d4f6e24ef8bad33a0bbecb8c07aff SHA-1: d78f2b81265d1e55116dcf9bb319a90510566d9f SHA-256: f675d3a86907957c988ef89a98fa0dd5e30306e9cc10f413f80f2b14ff739683
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest a phishing or trojan payload is being distributed through these links. No scripts were extracted, but the structure and URL patterns are consistent with phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9829

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://oniceh.ru/uplcv?utm_term=a+high+pitch+sound+has
    • http://tanphatinst.com/vietkiendo/upload/file/79341683478.pdf
    • http://studiomontironi.eu/userfiles/files/revarekumagojutenol.pdf
    • http://maxgear.cz/webpagebuilder/ckfinder/userfiles/files/bekikatogewibifuwewagev.pdf
    • https://viettincapital.vn/upload/files/38736925445.pdf
    • http://safarang.com/basefile/files/43109612273.pdf
    • https://kcharp.com/ckfinder/userfiles/files/38090829887.pdf
    • http://eko-gospodarstwo.eu/files/file/60330007726.pdf
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/mp98d695lhj696b1sa3l3mp0k1/14706171010.pdf
    • https://www.ijmsir.com/ckfinder/userfiles/files/49989107386.pdf
    • http://gomientrung.vn/uploads/image/files/rubalijukoku.pdf
    • http://tractortools.cz/ckfinder/userfiles/files/6705418029.pdf
    • http://k2plusinterior.com/userfiles/90430441363.pdf
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145a573bb86d---66133439473.pdf
    • https://buyafranchise.org/files/files/turigipisatibo.pdf
    • http://chongthamnguoc.vn/img/files/55040060168.pdf
    • http://ski-experience-japan.com/images/blog/file/takufaweniwebakez.pdf
    • http://bsbcarpet.com/userfiles/file/71263355782.pdf
    • http://irinaburmistrova.ru/files/39328498929.pdf
    • https://chilegastronomia.cl/uploads/userfiles/files/51897664423.pdf
    • http://coeb.eu/userfiles/files/xuvaxa.pdf
    • http://daotaoyduoc.org/wp-content/plugins/super-forms/uploads/php/files/fd7ba1ff8db75552eeec797cbc0cbcfb/45816862691.pdf
    • http://sosnovgeo.ru/userfiles/file/74777829785.pdf
    • https://livewireeventz.com/userfiles/file/numoko.pdf
    • https://hkpefa.org/editor_upload/file/kulusev.pdf
    • http://kdsonline.org/userfiles/file/78807337523.pdf
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/09ba56775949291ab5bab0f5ae2c551a/vutakujezetosazonefowuvak.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_off0000cb9a.bin
f08109dc945475c879b2355a1c8b052912aa6ad504bae3cacb973449af4b8a44
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB9A 17464 bytes
font_01_sfnt_off0000f899.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF899 16792 bytes
font_02_sfnt_off000110b0.bin
2094afea1de86ec846e38a35f2535739939d270cef1e92b61058e887c73a2fee
pdf-font-stream PDF embedded font (sfnt) at offset 0x110B0 10596 bytes