Malicious PDF — malware analysis report

Static analysis result for SHA-256 28cc9599d1ffb7f0…

MALICIOUS

PDF

123.6 KB Created: 2021-09-05 18:26:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 945013b558acefce8f9b6f99c8f6af5e SHA-1: f34ea917a3119589afecce6ab16d519007a4ccae SHA-256: 28cc9599d1ffb7f014eb26d755d129723e114305c523c1f16b81ec288487c96c
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable hosting, suggesting a link farm or phishing lure. The presence of multiple PDF link farm heuristics further supports this. No scripts were extracted, but the overall structure points to a malicious PDF designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/16c1455b593078e64b823923f0a8f9df/nivobepukexagedipoxi.pdf
    • http://suaups.net/userfiles/file/71710614645.pdf
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/160989cbaa3632---67093445302.pdf
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160984f5cb1a8d---11477754949.pdf
    • https://bistakalikotenetwork.com/userfiles/file/36053569663.pdf
    • http://ailizia.com/userfiles/makalirusotoxowifivugoge.pdf
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ec4c22727ba---rexuburatarikugatomene.pdf
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/fbf015efc5f3d2e4bf93019325976e82/42824642704.pdf
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/1a6c5c84b830211c108c058565222ff8/56901579094.pdf
    • http://fred-robin.com/ckfinder/userfiles/files/gumanufusoku.pdf
    • http://abwingsva.com/uploads/files/dulojudipabezudomepudi.pdf
    • https://cal.lighting/wp-content/plugins/super-forms/uploads/php/files/219563423cc967a9c6308388d4a5e066/kepisutexowodojotamavo.pdf
    • http://adamlegal.com/userfiles/file/93078332899.pdf
    • http://vasvaripalmuzeum.hu/upload/file/rinasonobowedadusak.pdf
    • http://architetturaurbanistica.it/userfiles/files/kesanufadatalaxi.pdf
    • http://cambresisemploi.fr/ckfinder/userfiles/files/situzapatovujuguzi.pdf
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071fff49d388---kogadafudugabem.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607379f1b468c---30299025635.pdf
    • http://1utilaje.ro/mm/file/terisutekez.pdf
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/6da5c3333209b33a914fb88e5491ace4/bivelawexexomewesu.pdf
    • http://gourmethousemacau.com/UploadFilesfile///3381822239.pdf
    • http://ctyrkolky-gamax.cz/data/dokumenty/gitepa.pdf
    • http://ave-france.com/pics/files/zevotalaxob.pdf
    • http://vogiantinhmach.com/media/ftp/file/99593923729.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=hands-on+deep+learning+with+pytorch+pdf+download
    • 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_off00017ab9.bin
06c17d019962e0a3cc05716513c6ae0a812b200e68fe25e8e8a27de92f016e04
pdf-font-stream PDF embedded font (sfnt) at offset 0x17AB9 19284 bytes
font_01_sfnt_off0001ae16.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1AE16 16792 bytes
font_02_sfnt_off0001c62d.bin
172006dbd06fab0b7b39ad3e517c0f082b4a8cfd5d4e153dca4fe873468db2c4
pdf-font-stream PDF embedded font (sfnt) at offset 0x1C62D 11124 bytes