Malicious PDF — malware analysis report

Static analysis result for SHA-256 3790672259c80ad0…

MALICIOUS

PDF

69.2 KB Created: 2021-10-01 19:50:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 65df3a7b72ec62dbb772d7eb5bcc9dac SHA-1: c2190fcd2ad88ec0db5cad8d1f71423c75be911c SHA-256: 3790672259c80ad0c645c5ad01dd0115b57a31a73f8e76f4f1f2d48aa1db38ed
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Multiple external URLs are present, some pointing to compromised CMS upload directories, suggesting an attempt to lure users to malicious content or phishing sites. The PDF structure itself is also noted as having duplicate object bodies, which can sometimes be used for obfuscation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/a2372d66c6342dbf76fe3c08077900cc/zitenaludarelukerimiga.pdf In PDF document text
    • http://enjoyisagenix.com/ckfinder/userfiles/files/45253965973.pdfIn PDF document text
    • http://uptownfallschurch.com/uploads/files/pifeveditagilififet.pdfIn PDF document text
    • http://dansungsala.com/uploads/files/90869125068.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/1697583113614595d36f262.pdfIn PDF document text
    • http://hzyixiangchem.com/upload/files/87830568444.pdfIn PDF document text
    • http://rujiahk.com/uploadfiles/file/134371551.pdfIn PDF document text
    • http://wernersuarez.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vuvatawivumokobeni.pdfIn PDF document text
    • http://855solution.com/htdocs/cljr/data/files/68736256351.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/2fe5bf1761d3f03beab82e3016410601/posow.pdfIn PDF document text
    • http://residencecarlofelice.com/userfiles/files/lakejedeguzenipusebodiku.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161518167e6618---kovaxipenenijuvob.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161408357e581f---25590763884.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614212552b034---vomozivizezitawe.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133c65d3929a---3850938635.pdfIn PDF document text
    • http://chinazzjx.com/d/files/vasevujujanomejego.pdfIn PDF document text
    • http://workontext.ru/media/file/kifijabi.pdfIn PDF document text
    • http://ckrestaurantgroup.com/ckfinder/userfiles/files/76990198308.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/31325514887.pdfIn PDF document text
    • https://burlingame.com/wysiwygfiles/file/sisemi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=copy+text+messages+to+email+androidPDF 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_off0000acdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACDD 10984 bytes
SHA-256: 0cc174524428112d0e9c63271eafb573ca0869fe5720bb44124f61a8b9e5fe4f
font_01_sfnt_off0000c633.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC633 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000de45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE45 16112 bytes
SHA-256: 79a9a0ec50b6cc4e270cba20eea7045c71277255105eaeb89e0214be81c42228