Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d77af3dfbbc66b3…

MALICIOUS

PDF

87.0 KB Created: 2021-07-15 22:35:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 867280fb45f4e6afbffb0f83e87b01f6 SHA-1: e3c5e9dbc8a8276b39f2c7d22bf2962f73ee15aa SHA-256: 8d77af3dfbbc66b34cb61f0b531a695d6e248c0cb3a2e62d9f027bfd3b62f760
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by a machine learning classifier and ClamAV as malicious. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The presence of external URIs and link farms indicates an attempt to redirect the user to external resources, likely for further exploitation.

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 https://krisoc.ru/uplcv?utm_term=how+to+start+a+fire+with+a+flint+rod PDF link annotation
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/2dfaaad881c9aec5cad8d81da6b1cf47/1552380543.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/cec74769a385be01eaabbc494da89fe9/13050552940.pdfIn PDF document text
    • https://pharmawell.eu/ckfinder/userfiles/files/73899018928.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/be89df159eec7bb625987b8d3cfdeb4b/mugekokigufa.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/160754bd7594ea---78465377777.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160e6588b1c5c8---xugininixumubagejok.pdfIn PDF document text
    • https://netpage.info/userfiles/file/98799755996.pdfIn PDF document text
    • http://aroma--style.net/files/files/9508521097.pdfIn PDF document text
    • http://bagiez.de/userfiles/file/likemoxudilik.pdfIn PDF document text
    • https://www.sadcmedia.com/wp-content/plugins/super-forms/uploads/php/files/i0058cnrtgc3lu4tc7pj4kbkof/lufibunapekifisewapokuvo.pdfIn PDF document text
    • https://cruiseship.cruises/wp-content/plugins/super-forms/uploads/php/files/kfsmttkuf5fu861ut3op3dlvpn/velobaresefijozigo.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090a9b7a1466---daviroxisoga.pdfIn PDF document text
    • https://northstarexecutivesearch.com/wp-content/plugins/super-forms/uploads/php/files/8a3e75044bfadb92dc60d7b938250f26/mufefa.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/87n85dni4e1vevh3700j32kglp/78172994560.pdfIn PDF document text
    • https://gamepinleri.com/calisma2/files/uploads/sideputewovubevozumuwuw.pdfIn PDF document text
    • http://donghocasiochinhhang.net/uploads/userfiles/file/9202214209.pdfIn PDF document text
    • https://stayatrosetta.com/wp-content/plugins/super-forms/uploads/php/files/u5kar91qo1hloshqa4bijuu57i/zagew.pdfIn PDF document text
    • https://bestofbucerias.com/upload/file/49582956562.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/nu6lme25miblj8r3cpg4u9an34/wuvafa.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/guputenuxirudixezorumox.pdfIn PDF document text
    • http://kojeneckezbozi.eu/userfiles/file/93172336866.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f57e234df6---83581631975.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160978490f05fa---pijividewefejenukezeju.pdfIn PDF document text
    • http://matsonconstruction.net/userfiles/file/75443733345.pdfIn PDF document text
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/b11e0f95a0c80aac22779d59816dfe41/36487739903.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eeeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEEB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010702.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10702 10528 bytes
SHA-256: 8f9eb0b70321f78a77d4ffe2d09b55d7afc17237800fc4639046f32314795f06
font_02_sfnt_off00011ee7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EE7 18172 bytes
SHA-256: 4e111404e8c17014ce441a68d4d699ff14bf772b666017b04754d67054b6cfec