Malicious PDF — malware analysis report

Static analysis result for SHA-256 0dc48878237b608a…

MALICIOUS

PDF

85.5 KB Created: 2021-09-13 14:48:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 101a71cf3358b6db521dc5dd428e0822 SHA-1: cf37565dc3a9128dbcbdffdbdf88b57ba8645a72 SHA-256: 0dc48878237b608acbb48ffe9b733a954c1bf07816d13e6cf62b9c3d8a2c1425
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external resources, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to distribute further malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards the exploitation of PDF vulnerabilities or social engineering to trick users into downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://honkakuji.jp/honkakuji/images/ckfinder/files/vinogosip.pdf
    • https://tainandentist.com/uploads/files/202109050051159840.pdf
    • https://audreyheselmans.com/_files/file/89432411046.pdf
    • http://bumsnab.ru/uploads/files/95222080274.pdf
    • https://cnn-logistics.com/asset/files/tugoviwumitekapatavo.pdf
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab0a346d86---8468742922.pdf
    • http://www.peritaonline.es/ckfinder/userfiles/files/bumenamusimepugikik.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a5c3710831---bijojalalafonovexakojuwa.pdf
    • https://speedwayinfo.hu/uploads/file/86747592001.pdf
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d058a435c2---39730974942.pdf
    • http://wakesup.org/userfiles/file/28897010423.pdf
    • http://marmaraisg.com/images_upload/files/papod.pdf
    • https://hoavily.com/uploads/files/besazegijo.pdf
    • https://xn--22ck6bdp5cach0mc23a.com/ckfinder/userfiles/files/15894471574.pdf
    • https://thefertilizergranulators.com/d/files/tiwuzisirerago.pdf
    • https://stthomasorthodoxchurchsouthpampady.com/userfiles/file/vazet.pdf
    • http://zekidilektekstil.com/images_upload/files/40253694232.pdf
    • http://ty6600.com/userfiles/file/jomofuzefanoxewaxutamef.pdf
    • https://www.phuketvillarentalandservices.com/ckfinder/userfiles/files/zokuwosagegofile.pdf
    • https://www.domosystem.gr/ckfinder/userfiles/files/basiduwalakogujasugozum.pdf
    • http://forglass.sk/userfiles/file/26973100261.pdf
    • https://zahrek.com/userfiles/file/2929739910.pdf
    • http://thai-apsproducts.com/file_media/file_image/file/bavirebadesavu.pdf
    • https://taperagi.com/contents/files/5231813242.pdf
    • https://hideab.se/tc/Mediagalleri/file/30691738063.pdf
    • https://jotelek.hu/files/file/56242109407.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=machine+learning+for+cybersecurity+cookbook+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_off0000d9f5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F5 16792 bytes
font_01_sfnt_off0000f20c.bin
023dad708979a541f33720ab8d2674c731309fe18eec57b5c9fdbf01c2a3fba4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF20C 11340 bytes
font_02_sfnt_off00010c4c.bin
1e2d72cfc71c8f73b9a3ca61be6ef04d9426daef517c1d5e9026b17432cd2a00
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C4C 23032 bytes