Malicious PDF — malware analysis report

Static analysis result for SHA-256 c738316123e46a8c…

MALICIOUS

PDF

75.4 KB Created: 2021-10-05 04:45:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 6edd8f55dc7a6d97d5c93f09aca7300d SHA-1: 964b4f56b1ac6b6b1b30f2df2364e24e2e05b8f2 SHA-256: c738316123e46a8ccb49e2f900a35ccc523faf52679182fad19a0ccd26c4be03
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to various websites. Several of these URLs are hosted on compromised CMS upload directories, indicating a potential distribution or hosting mechanism for malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://francescasciortino.it/userfiles/files/96046058997.pdf In PDF document text
    • http://wmsone.com/eimages/file/lorekilokavujotikaxu.pdfIn PDF document text
    • https://srldirect.com/ckfinder/userfiles/files/disunip.pdfIn PDF document text
    • https://www.sesc-am.com.br/Selecao/ckfinder/files/burifev.pdfIn PDF document text
    • http://modero.vn/upload/files/tudibazosewek.pdfIn PDF document text
    • https://bostoncake888.com/UserFiles/files/58265141547.pdfIn PDF document text
    • http://nieruchomosci-swidnica.pl/userfiles/file/koruvagekovugixesi.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161376ae4b08f4---voloxozes.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/161431ff2cbfb0---5107303415.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/570mc413ph2s4fth5ku5lbtov2/momowewufidedu.pdfIn PDF document text
    • http://gaushalango.com/uploaded_files/userfiles/files/mokinerosebitavigopep.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615612fed5fcf---85387709763.pdfIn PDF document text
    • http://yanarfabrics.com/firma/files/17882656903.pdfIn PDF document text
    • http://vietnam-intraco.com/webroot/img/files/devodimodijetogepurewuseg.pdfIn PDF document text
    • https://heart-calligraphy.com/uploads/files/202109241606427804.pdfIn PDF document text
    • https://laznia-radom.pl/userfiles/file/31270738712.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146d0ac6be0c---28234371401.pdfIn PDF document text
    • http://qapoll.com/2015/vat/upload/files/981459307.pdfIn PDF document text
    • https://ehlibeytalimleri.com/resimler/files/52225884275.pdfIn PDF document text
    • https://alatheir.com/atheirwsfiles/file/49011485104.pdfIn PDF document text
    • http://pfollowers.com/ci/userfiles/files/27134051910.pdfIn PDF document text
    • http://bociany.sk/media/file/majiguk.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/d439b136ac8b660d7c1065cd0ca78d5e/95101733511.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=lust+as+a+sin+in+the+biblePDF link annotation
    • 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_off0000c3f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3F8 17496 bytes
SHA-256: fdba4922f3ec8fe41b7613d49b21dc9b842354d8b947c437eb0412c22aab457c
font_01_sfnt_off0000f12c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF12C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010943.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10943 10180 bytes
SHA-256: 5bf8141e816591b03639a28f4789b097327fdcd463babf2b86a69bbaf639d871