Malicious PDF — malware analysis report

Static analysis result for SHA-256 55a9aeb91357c647…

MALICIOUS

PDF

84.7 KB Created: 2021-10-08 12:00:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 26ba0149f8900166cafc02b993b3952b SHA-1: e03a4eb2a5bafa9ec8b2604bb669ca062e019bf2 SHA-256: 55a9aeb91357c64760e12d872bf9bae4fe998bd31e097b22dddec8eee0f77d31
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories, indicating a link farm designed to host or distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://hrudolf.com/userfiles/7769021100.pdf In PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615a9330d108a---85727979979.pdfIn PDF document text
    • http://farmaciafoglia.eu/userfiles/files/86500742375.pdfIn PDF document text
    • http://imhang.com/fckeditor/userfiles/image/62195185341.pdfIn PDF document text
    • http://ig-einheitsloks.de/medien/file/wejuf.pdfIn PDF document text
    • http://tyros-club.de/userfiles/file/sunolegopediriwonuxox.pdfIn PDF document text
    • http://kelsenator.com/userimages/rogerovuratef.pdfIn PDF document text
    • http://lovesushiscv.com/uploads/files/suteropexinanita.pdfIn PDF document text
    • http://creptiles.dk/userfiles/file/54473472670.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135b25045d4c---mezewosopajelif.pdfIn PDF document text
    • http://re-media.ru/foto/ck/files/norenopeteliwofukikuna.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021092504320550.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/13060904823.pdfIn PDF document text
    • https://tessuno.com/upload/files/615074e573e7c.pdfIn PDF document text
    • http://www.ecrivains-consult.fr/easyonline/ckfinder/userfiles/files/22924768226.pdfIn PDF document text
    • https://aljuboori.com/userfiles/files/94580292798.pdfIn PDF document text
    • http://praguetransfer.com/files/file/52853304092.pdfIn PDF document text
    • http://gorisum.net/fckeditor/upload_file/file/33053848443.pdfIn PDF document text
    • http://diplomat2014.ru/ckfinder/userfiles/files/27799782242.pdfIn PDF document text
    • http://88cpap.com/userfiles/files/2658014354.pdfIn PDF document text
    • https://www.bnbtravels.com/ckfinder/userfiles/files/3546315830.pdfIn PDF document text
    • https://mccartha-cobb.com/userfiles/files/18117012972.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142666f4019a---darebilukoxeb.pdfIn PDF document text
    • https://all-stage-meditation.tw/uploads/files/615f4a4807060.pdfIn PDF document text
    • http://sushiloverca.com/uploads/files/padodezejevi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=convert+document+to+black+and+whitePDF 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_off0000e338.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE338 18728 bytes
SHA-256: a3f90589380c4fcc8bf1fccc9274af0246f35ed59d65431ee70a780eff4ecc90
font_01_sfnt_off000113a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113A7 10984 bytes
SHA-256: e50493909e28e24ffb3133634da89046636ee39460d128f9623771c7bfadcb1c
font_02_sfnt_off00012cfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1