Malicious PDF — malware analysis report

Static analysis result for SHA-256 23d531ab3cb747d5…

MALICIOUS

PDF

86.5 KB Created: 2021-07-29 17:43:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dc2f6f1fe5f7cb752c363d26700fdfa8 SHA-1: a67c62a6525348e66176c68068ceb252dca288e9 SHA-256: 23d531ab3cb747d53a6986fa169a01ed434b8a2f2225f59d4cc1b50f5039d475
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including ClamAV detection and an ML classifier. It contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution scheme. The presence of embedded URLs indicates an attempt to redirect the user to malicious content, likely leveraging a PDF exploit or social engineering.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160c9a0f8543f0---62649773438.pdf
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/3edff63a7e8ce25a57c34272eabb4f65/molijugetuvonafibip.pdf
    • http://polyacer-ecp.com/userfiles/files/20210722_100135.pdf
    • https://kumsalgame.com/calisma2/files/uploads/64666265169.pdf
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/53595d61419f938f071a86bb4451e11b/40554430432.pdf
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/a2jcobvtkd80m5qnl97k8kaisv/13622447582.pdf
    • http://kemmurad.com/webroot/img/files/jewozinilus.pdf
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160adf863b25bd---xozalejo.pdf
    • http://colescastle.com/clients/875019/File/nomegipivudunujevaminil.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a30493bfba7---14448603223.pdf
    • http://beerskiboot.de/img/upload/file/kedebutifuxomerigojunij.pdf
    • https://capitalsyndic.com/userfiles/file/fotelevuxifat.pdf
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/bc62a2316a5e5c12e4af6e78b7b24e16/536138875.pdf
    • http://cityclick.it/userfiles/files/tizoruzewalukiradatixiwan.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/v3r8cvpfg47hq1jub78kco3c11/ganidijajefigepotezafazo.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160ae836d19fd6---towire.pdf
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608446cdae83c---88127656409.pdf
    • http://musorcentrum.hu/files/article/file/titimawelupegi.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bfec34f2804---74490673261.pdf
    • http://veterina-hrib.cz/user-uploads/files/98624700470.pdf
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160871ab608d34---bifapa.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=%C2%BFcu%C3%A1les+son+los+niveles+normales+de+glucosa+en+el+embarazo
    • 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_off0000ec7e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC7E 16792 bytes
font_01_sfnt_off00010490.bin
9fb22ee2475c76f109ce82e1c0f87453d7201ea859e3c413f27adc62593e73a3
pdf-font-stream PDF embedded font (sfnt) at offset 0x10490 17064 bytes
font_02_sfnt_off00012fcb.bin
6d95cbfdf2e94b45215db21f4d3c74d9a3cb97b4e815bab2063d940c0639388b
pdf-font-stream PDF embedded font (sfnt) at offset 0x12FCB 11216 bytes