Malicious PDF — malware analysis report

Static analysis result for SHA-256 544eab8be77da372…

MALICIOUS

PDF

105.2 KB Created: 2021-08-11 23:16:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bfbb702b8178b664a6d739ba316bcd95 SHA-1: 1dfd0d4ff05d38bcbe835ee003e95c2ccd75843d SHA-256: 544eab8be77da37250a82da57f13a148dde66f2abc754406e9685dd02da85f68
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to potentially compromised WordPress upload directories, suggesting an attempt to redirect users to malicious content or phishing sites. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 6

  • 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 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://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/a140decf2a3b0933be01451874d0dd88/8260510605.pdf
    • http://idcla.net/upload/files/bibekojidejuwumedab.pdf
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/gh8cor73t2hjq5vb1so73iknfa/zekigopomudevi.pdf
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/6cc038e8882d4b5b985e4650a6bccf8e/71992703929.pdf
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/bcudulkqaoo7u641jbc6m0vgh4/nokojizulisuwob.pdf
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606f99742368a---93042172753.pdf
    • https://supportsystemsvainc.com/home/ssvi/public_html/ckfinder/userfiles/files/34831283690.pdf
    • https://idd.no/ckfinder/userfiles/files/49967338646.pdf
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/160982b23933f8---44789598376.pdf
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/a168ac0556c5d382bff21a384397c627/rivakowusup.pdf
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/ae3ee5f1baeb4fb7cdbce1519e58239e/kaduguvezos.pdf
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d255c9382d---84219410221.pdf
    • http://klawiatury-foliowe.pl/_data/file/zirazixoxufusojo.pdf
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1610a0197269e3---83409708379.pdf
    • http://neodentpetrosino.it/userfiles/files/25581913806.pdf
    • http://dok-vo.ru/userfiles/file/32205351322.pdf
    • https://www.alignerco.ca/wp-content/plugins/super-forms/uploads/php/files/1727c0085d45016ccf27f189e8c65348/72491866923.pdf
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/402e0f1542984160c423e3f083aa2b61/25155795363.pdf
    • https://sankaibearing.com/userfiles/files/11592896814.pdf
    • https://psychotherapie-coeppicus.ch/userfiles/files/41933828630.pdf
    • http://qhs1978.com/clients/d/dd/dd8db5a278a7ad55a2ada34b8e38ebcc/File/fadukaw.pdf
    • http://rickgrisolia.com/userfiles/files/rupifonelizekap.pdf
    • http://lobi.md/userfiles/file/fupujisulolavevawa.pdf
    • https://chpcentre.com/files/file/69783164749.pdf
    • http://njuhome.pl/ckfinder/userfiles/files/87901776921.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=what+are+the+3+curriculum+design+models
    • 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_off00013665.bin
c2fe35b0bcff88c9d1759eb8e09beb7aee70972e5fb7dabe7082aef36020bdf7
pdf-font-stream PDF embedded font (sfnt) at offset 0x13665 18116 bytes
font_01_sfnt_off00016559.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16559 16792 bytes
font_02_sfnt_off00017d70.bin
61137949bf5ded2eeac37b047b431dac60d29c164017f85be116fcc3025b0e1c
pdf-font-stream PDF embedded font (sfnt) at offset 0x17D70 11080 bytes