Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b1c4955705289fd…

MALICIOUS

PDF

94.3 KB Created: 2021-07-24 16:06:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 49f6e835419d3f276e234313964a6587 SHA-1: bf89a764f8eeb25280f3d6e3a855e33c1f2f7fb6 SHA-256: 8b1c4955705289fd154d18a6fc8c731edbfdfe3680a720b37a88b98f6139a5ad
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. The PDF also contains a large number of external URIs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious destinations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://accessiblevehicleservices.com/userfiles/file/natuvawune.pdf
    • https://tenfci.org/userfiles/file/37027342444.pdf
    • https://vietucmould.com/img-vietuc/files/vufijubuzopoketadagawi.pdf
    • https://www.vek-bg.com/app/templates/js/ckfinder/userfiles/files/binavavujubot.pdf
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160975ec3eef97---rinejapixukinine.pdf
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/0ebmbrnfmaq1noojenovealmfq/69414019737.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a16e8c820af---97945539311.pdf
    • https://primewestelectrical.com/wp-content/plugins/super-forms/uploads/php/files/931b00d8e7c2da526c0b448e55476cd6/36739759879.pdf
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/bb8c44b4ca5530d159a3ad0c8f31ee50/29758464966.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080e2b8c3e45---zilefakuzenedasujewawax.pdf
    • http://kco.su/userfiles/file/31771422713.pdf
    • http://newfieldclassof1982.com/clients/6/69/69e49ffade321d977af769e13f9f004b/File/voxaxedok.pdf
    • http://livestocktool.com/d/files/41370732246.pdf
    • http://skrabl.pl/www/rpbd/fck/file/roliraxefefibowefixuzum.pdf
    • http://billsky.ee/files/file/jumun.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/16075d5ced9a42---6988609142.pdf
    • https://eravukappalpalli.com/userfiles/file/34033175981.pdf
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dbb83e15c95---99381120871.pdf
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/ch0m4jsjonact2dkq238r06kn8/goluko.pdf
    • http://svazekobciorlice.cz/userfiles/file/dirowimolulefe.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/am84lbv0q0rjp1h810djih6mu3/88559987759.pdf
    • http://amirafouad.com/uploaded_files/file/60326771182.pdf
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/160746c891e5e3---jorutezuvepegunodepaxaf.pdf
    • http://op-gold.com/ck_image//files/27468637650.pdf
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/82448823353.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=how+to+write+a+guarantor+letter+for+work
    • 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_off00010f3f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F3F 16792 bytes
font_01_sfnt_off00012751.bin
0f3de7028932bb12aaf0f12481015e8dd5a6171ad8a8c8a10db6c0608ec3b8e4
pdf-font-stream PDF embedded font (sfnt) at offset 0x12751 16884 bytes
font_02_sfnt_off00015360.bin
b9d11179b3a1fc3df5221777d5f8183a95fe2ccf14e43792c977b197d584816b
pdf-font-stream PDF embedded font (sfnt) at offset 0x15360 10492 bytes