Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ad891b31cdc78d5…

MALICIOUS

PDF

76.8 KB Created: 2021-09-29 01:20:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c59535999dc9a993b81729222e93ed76 SHA-1: d0cd02206387fe6be40633bea879546881845b01 SHA-256: 6ad891b31cdc78d553114f48384114c9981c1d2933eb08f8e6de897ed64fdd07
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to other PDFs hosted on compromised WordPress sites and disposable domains, indicating a link farm designed to distribute malware. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were directly extracted, the PDF structure and URL patterns are consistent with a phishing or downloader campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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 http://www.detskaoptika.cz/ckfinder/userfiles/files/zelivoka.pdf
    • http://rileyillustration.com/images/agency/files/63787869167.pdf
    • https://daqing-jewelry.com/uploads/files/202109200912191661.pdf
    • http://twfindia.in/userfiles/files/xiberedawaneledi.pdf
    • http://jfhcoaching.nl/userfiles/files/5821277709.pdf
    • https://simbhaolipower.com/images/file/jilatewugesimisaxemim.pdf
    • https://ww150003.linebot.net/upfile/files/20210912193733.pdf
    • https://www.pepinieres-gey.fr/ckfinder/userfiles/files/18871232039.pdf
    • http://packturf.fr/files/48641406781.pdf
    • https://pensiuneavalentina.ro/app/webroot/file/busanubuda.pdf
    • https://lorus.rs/files/71012700957.pdf
    • https://krainaogrodow.eu/zdjecia/fck/file/91368084935.pdf
    • http://innovad-ltd.com/userfiles/file/45381896237.pdf
    • http://clinicaveterinariacittadivignola.com/userfiles/files/xilum.pdf
    • http://www.gabrielamaciel.net/images/content/file/44411458846.pdf
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/8hocus2iihvjj1c7925dqe6jkd/xirizeragu.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/161341e92aeca6---6952224257.pdf
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/16137ad01d9799---72445622225.pdf
    • http://uniquecharacters.com/upload/files/75201952192.pdf
    • https://associazionedynamica.it/uploads/file/xesusapa.pdf
    • http://electrogalicia.com/electrogalicia/recursos/archivos/solumeradedej.pdf
    • http://fujavietnam.com/images/Download/pilevewijavubav.pdf
    • http://toanlinh.vn/upload/files/61297817386.pdf
    • http://www.afurg.com.br/assets/ckfinder/userfiles/files/1284415695.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=western+survival+mod+apk
    • 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_off0000c164.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC164 16792 bytes
font_01_sfnt_off0000d97b.bin
6653bf75f6b27d1edbe036942b88007a9ada3676b9ea73f39b1813f7e3e6317c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD97B 10804 bytes
font_02_sfnt_off0000f263.bin
af26fcbc88def436aa9b84f784c16fa1710daa1314d427beb3c6b55f7f90731e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF263 19948 bytes