Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9f0337cff6f6782…

MALICIOUS

PDF

75.2 KB Created: 2021-09-11 09:44:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 57920bc7de184f6c6277ae30ca60f21e SHA-1: 73fd4d0e9bc73f2ea292c7cb5a0dd86b4a258c2f SHA-256: f9f0337cff6f67820861d7745f5d7a1ef4b74212893e03ccf1b4fe8257a3748e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest a phishing or trojan payload, likely delivered via spearphishing. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 https://wastran.ru/uplcv?utm_term=minecraft+pocket+edition+acmarket PDF link annotation
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1613325cf81584---61443857995.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/992da28a50c74811df9f28b121a1cb91/75134825492.pdfIn PDF document text
    • https://fotokeramika.bg/userfiles/file/61477729209.pdfIn PDF document text
    • http://groupkaishan.com/d/files/92579113454.pdfIn PDF document text
    • http://beijingteye.com/upload/files/24381539787.pdfIn PDF document text
    • http://pujcovnanaradi-tvarozna.cz/userfiles/files/kakogas.pdfIn PDF document text
    • https://blsautomation.com/ckfinder/userfiles/files/wesevo.pdfIn PDF document text
    • http://learnazia.com/fck/imagesfile/54758888464.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16132c215703ef---mabimopuwixinalitazulopaz.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131c5676b937---64111038745.pdfIn PDF document text
    • http://railwaysrailroads.com/upload_files/files/feraxipatikik.pdfIn PDF document text
    • http://krr-nfe.com/suratnfe/UserFiles/File/ninepokasadoleweruxika.pdfIn PDF document text
    • http://shceping.com/upFile/photos/2021-9/file/75551140232.pdfIn PDF document text
    • http://master-vin.ru/files/file/41556667755.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/siwexorebi.pdfIn PDF document text
    • http://npk-bypassdrr2.com/file_media/file_image/file/73389130365.pdfIn PDF document text
    • http://montpellier-business-plan.fr/mbp/upload/images/images/upload/ckfinder/leridalutubimalipene.pdfIn PDF document text
    • http://saothienemb.com/uploads/images/files/46736507943.pdfIn PDF document text
    • http://myucmas.com/userfiles/file/95108871868.pdfIn PDF document text
    • https://buddhaart.in/userfiles/file/88389972943.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/161316391cd524---75488029104.pdfIn PDF document text
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/kixewofisitotipo.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_off0000c22b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC22B 10652 bytes
SHA-256: f30271bbba266fba7bb761a95eda88199ca84dafee6ea9485676b4aa7974e1cf
font_01_sfnt_off0000da87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA87 17488 bytes
SHA-256: dcd505516849e5f29964a0021539ddad5b9679e1e8221f57bcf3888bf015e608
font_02_sfnt_off0001078a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1078A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1