Malicious PDF — malware analysis report

Static analysis result for SHA-256 90b23e4da2c68b37…

MALICIOUS

PDF

74.5 KB Created: 2021-07-14 10:31:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81ce6574127bce17de0580b0654d87e5 SHA-1: 620c21b5a5c9ae9e4f624a9ff3fb7368db2ea696 SHA-256: 90b23e4da2c68b376a27ef272b76106b47a017ae039db88af39503b690e3c42b
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and a machine learning classifier. It contains a link farm pointing to multiple URLs, many of which are hosted on compromised WordPress sites or disposable domains, suggesting an attempt to distribute further malicious content. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a pattern of hosting malicious files on seemingly legitimate but compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://plafondchauffant.fr//img/user/file/51950371480.pdf
    • http://abacusnancy.com/userfiles/file/vixemarafipuvovozenowi.pdf
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9abcea517c---votuzezobefagajeb.pdf
    • https://cplastik.com/data/cms/file/16170194235.pdf
    • https://communeouchamps.fr/userfiles/file/rutukavusenawoxinawux.pdf
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/199bcafe2c44c949a614c10007cc56be/gepafibajabi.pdf
    • http://developmentassociationofnagaland.org/nbloom/fckuploads/file/18258462830.pdf
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b99340e8341---resutewigugukexipibogil.pdf
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/9768dff2bef99334c0f483ccd6b4f0c3/26327872801.pdf
    • http://studio-rivetti.it/userfiles/files/68153269093.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3b278364e3---fetafuxisasejetosod.pdf
    • http://abogarestudio.com/userfiles/file/51885509512.pdf
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/65821c97f1a072adf44e15572b1b106f/83585075877.pdf
    • http://lnianemarzenie.pl/userfiles/file/xufelitinakar.pdf
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/caf2cb136859ed72bb7175ad73152fe0/raloduru.pdf
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/3925932a0b95283d96d97cc21f26dfa6/3440185907.pdf
    • https://loctra.net/userfiles/file/bufenuru.pdf
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/72385011905.pdf
    • http://wjvanderheidedienstverlening.nl/uploads/file/zuzitoxidunupam.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093017c26142---vuruketumum.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b35d0e6189---6258682835.pdf
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b389d73414---79470167474.pdf
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee38661db3b---tewutosasesanesexabogejo.pdf
    • http://tpokebar.com/uploads/files/pepanena.pdf
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c937b9dbd56---54911566941.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=21.58+correct+to+2+decimal+places
    • 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_off0000c062.bin
6a7db29a61e1d23e437331b1b01202cb603ad9ec2f4d572fa7701a61d8a3d8c9
pdf-font-stream PDF embedded font (sfnt) at offset 0xC062 11052 bytes
font_01_sfnt_off0000da41.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA41 16792 bytes
font_02_sfnt_off0000f253.bin
7f975bf9ca397678a4a1e63326bcb49b126eb5d09495442283e3ed660d8a39ba
pdf-font-stream PDF embedded font (sfnt) at offset 0xF253 16500 bytes