Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4cb584fd14a221e…

MALICIOUS

PDF

88.8 KB Created: 2021-06-27 23:15:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 95d17f900b7d5202641b53ed1a0d49ed SHA-1: 72cc20d8a0848a284837f6945a91682552f1199a SHA-256: a4cb584fd14a221e7f58037ca7189d759a9bab4e821b58b28556041f8b0ea799
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to external resources, many of which are hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely to trick users into downloading further malware. No scripts were extracted, but the presence of numerous external links is a strong indicator of a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://vickerycarpet.com/uploads/images//files/86917794935.pdf
    • http://chinocorporatechallenge.com/clients/6216/File/weburazalajafevemi.pdf
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/lt8pqrc4i42h4nn1r2b1lau0un/mubusepepifisoru.pdf
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/vanod.pdf
    • http://jp-cable.com/d/files/1861648783.pdf
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/ee529298d92c72018ea2e0376b5cfd8c/80480860881.pdf
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087623a81912---lajizoribarivu.pdf
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/lubizepuratenalime.pdf
    • https://bczenekar.hu/files/file/moxuf.pdf
    • https://www.haievent.com/wp-content/plugins/super-forms/uploads/php/files/1d9qj2nasrebes9vrvor9htbsd/bizunoxapububunep.pdf
    • https://mindspacepsytherapy.com/upload/ckfinder_temp/files/20210527235118.pdf
    • http://omatsuri.kr/data/userfiles/files/47524464203.pdf
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/d2e5b44797e30458df54ada8ea540ee2/35024702751.pdf
    • http://driver-jazda.pl/upload/file/wixagixujuzede.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097eb328f9e4---79124641171.pdf
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/d816c0a749df750148902e6ee7b116f1/19425239134.pdf
    • https://nanyangtextile.com/userfiles/file/29340102606.pdf
    • https://juniorclublivorno.com/sitonews/images_upload/files/vanodatazunafuka.pdf
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc23a844b3---45862217695.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074adbb3cf49---68179554452.pdf
    • https://asiabiru.com/contents//files/pivajakevobalifigipeg.pdf
    • http://pincailight.com/zk/UploadFile/file/2021061715425773499.pdf
    • http://safeabortionnepal.com/userfiles/file/19361970486.pdf
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084ae7ed805d---tosowirogako.pdf
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a39a47adbf7---16280918000.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=histogram+with+grouped+data
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/f513d744208466c36eb8d0cae6f3d617/97440298469.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_off0000f643.bin
05c31aeb5dd7ff17b27ca88c841b21d89f52e2018dc6f1e0db9a8f603b8ccab3
pdf-font-stream PDF embedded font (sfnt) at offset 0xF643 18008 bytes
font_01_sfnt_off000124b5.bin
8897595677ab5afa6a471fbc9b09bae1eeb630bd682dee9cc6821ac9d5a21b2c
pdf-font-stream PDF embedded font (sfnt) at offset 0x124B5 10864 bytes
font_02_sfnt_off00013dad.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13DAD 16792 bytes