Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c5913d4d5d5d5e8…

MALICIOUS

PDF

95.3 KB Created: 2021-06-26 19:05:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 37dfd691390e60ad345d5d8bec677947 SHA-1: db3032af050060c2d76f45f28580604a96bad63c SHA-256: 7c5913d4d5d5d5e84ea3f596c6de9a3dd7c4886a95227f96f984b300d4c802ac
156 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous links, many pointing to compromised WordPress upload directories, suggesting it's designed to host or redirect to malicious content. The document body is heavily obfuscated and unreadable, preventing a more specific analysis of its immediate user-facing purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://yummyschool.com/_UploadFile/Images/file/92732269649.pdf
    • http://shinies.ru/img/lib/file/luzali.pdf
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3099734ad---65970276736.pdf
    • https://rclurie.com/wp-content/plugins/super-forms/uploads/php/files/7e1986c56ba030432da281c211a6f816/76495865873.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/iq4imgeiojh7thimn45abfs4rp/28696321507.pdf
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/teqd482uq25amln0mkqgm7qmlr/79769571187.pdf
    • https://aannemingsbedrijfbarthulsbosch.nl/userfiles/file/4732141114.pdf
    • http://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/2740665384.pdf
    • http://iphysiology.ru/upload/xopiwageluworugum.pdf
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/bpk7fb1u0b65i2q9q9tq2a2t51/31476489430.pdf
    • https://ludifrance.fr/userfiles/file/lekuzutuzerudupelosa.pdf
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/qvs3q080c0r50g5rg8mt6gbvja/62169096630.pdf
    • https://vijyaiprismcrm.com/userfiles/files/susuwuwizav.pdf
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/5548517363.pdf
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/4t7erop3pg8io4c33v78dn0bf4/44968435480.pdf
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b04daec80a---sonatuxid.pdf
    • http://sonkertrail.org/clients/9/92/9260a3c387aed4615f72c72c3a1da295/File/lupuwigujavowo.pdf
    • http://abogarestudio.com/userfiles/file/subinubiresuvewimosilusoj.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/160becc56bd1f3---mezupanakajonema.pdf
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b18cd053d43---61013102135.pdf
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/0f77ed02347ab0002e61152107022c0e/paduzomulomogak.pdf
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d43a385cce---piloxodenelevetujiv.pdf
    • http://studiolegalezullo.eu/userfiles/files/dekewi.pdf
    • https://wtmasonry.com/ckfinder/userfiles/files/giziruzovebafidetan.pdf
    • http://mamaskitchenorder.com/uploads/files/45167743945.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=what+are+extensive+properties+in+thermodynamics
    • 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_off00010a14.bin
c52e291ecc2ab6af6bbed2c125d554afd70b41c5f70440f37751043f0ec820e3
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A14 19456 bytes
font_01_sfnt_off00013dca.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13DCA 16792 bytes
font_02_sfnt_off000155e1.bin
4f94b729a32bffe6f08102c9f559cecc48ed56d2155cb123fc14455556b55007
pdf-font-stream PDF embedded font (sfnt) at offset 0x155E1 11008 bytes