Malicious PDF — malware analysis report

Static analysis result for SHA-256 81931693d31a0779…

MALICIOUS

PDF

86.0 KB Created: 2021-07-18 21:14:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4798d274c8007f615817624182b304e3 SHA-1: 264b1417ad7eef3493e19eb09bcc5ac041082a41 SHA-256: 81931693d31a0779a326aa9ad63a37fa8d2a059c48e160c7b12682707af326a3
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress upload storage, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these compromised sites. No scripts were extracted, but the structure and URL findings are sufficient to infer a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a6194774359---33178830346.pdf
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16070d94ea7019---fowasekazadasivafaxelatid.pdf
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/9ba0c126fc1de76414b6a440d37a47ac/39919385497.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606faf22898ce---xazikopa.pdf
    • https://premiumtrade.ro/ckfinder/userfiles/files/nusiwejowisedizaranad.pdf
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/ibnnc4pa966c9b73fok8nmhokl/16544609812.pdf
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/rcff4jsrp2t2km9ofg23rsefc1/43847328943.pdf
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/vawivavudogumujugosazil.pdf
    • http://pileshoppen.dk/userfiles/file/dujudekipedatawuxoset.pdf
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/kps0o4tt38c8i1h3ipd36d9507/kovojazoromatifulujumuke.pdf
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c77d54ff83---lubiribotiwaboromijewojaf.pdf
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/fv4th8lcoi18dku3h6dogumr56/48054617801.pdf
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b88e11ea0a---74514180858.pdf
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/cd68837cf2f2d68f0e9ba01e280e96b0/7304817516.pdf
    • http://www.justgiveahand.org/wp-content/plugins/formcraft/file-upload/server/content/files/16098ba1f354ff---dinamowipojivulu.pdf
    • http://perrymanreunion.com/clients/f/f8/f8644f0eb9578147d5589f75b8c3e300/File/99555376954.pdf
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/92c6314e85495a1ed0e5eb5c3f761ae1/88939699707.pdf
    • http://goldnumber.info/userfiles/file/46490690866.pdf
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8a511ae1b---zarilolimewowuje.pdf
    • http://www.pics4us.de/userfiles/file/44805472271.pdf
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e21d3eba2f0---39527065049.pdf
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080c969d0650---5356374397.pdf
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/550c423bef075481beb6e2a1325af914/37546184757.pdf
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/160872ff17b576---lasusotatunijuxejepuz.pdf
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/b9dcab2fd186a15b97a10af8daac1167/puvuweferakefejewul.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=north+south+east+west+compass
    • 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_off0000ecb6.bin
49167819f97c4864f615a56210c80683abdac22015ac21b1e2be615e1a60e62b
pdf-font-stream PDF embedded font (sfnt) at offset 0xECB6 17916 bytes
font_01_sfnt_off00011a6d.bin
5d2ffeb8ef5680b74d2298ab7f3120fad5f1616c43dcbeb51cac510452890a00
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A6D 10560 bytes
font_02_sfnt_off000132ac.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x132AC 16792 bytes