Malicious PDF — malware analysis report

Static analysis result for SHA-256 31479e3752825f7c…

MALICIOUS

PDF

74.5 KB Created: 2021-09-24 16:22:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 40dfb8d955593d65299c9ddca547ee7d SHA-1: 833ca36cee3b62f1dcb74ab70d426d9dd35e016d SHA-256: 31479e3752825f7c745345dd113a6896c3ef0cc99aa871e832bcc28e889a5f4d
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or compromised CMS uploads, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF used as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://garglob.ru/uplcv?utm_term=photo+grid+and+video+collage+maker+apk PDF link annotation
    • http://ccsilver.kr/files/fckeditor/file/157577963761475ced7977b.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/71281652786.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/jirunesejevevikoro.pdfIn PDF document text
    • http://kirsanov-maslo.ru/uploads/15679453859.pdfIn PDF document text
    • http://movitecnic.com/ressource/site-image/files/46871393439.pdfIn PDF document text
    • http://hyunshin.net/userfiles/file/86416623514.pdfIn PDF document text
    • http://agriturismocorteerbatici.it/userfiles/files/wuwexisiretiguzipeneridif.pdfIn PDF document text
    • https://losungversorger.com/product/file/jidamogakazatibodixeme.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed844695c7---58549576850.pdfIn PDF document text
    • https://rumputhijau.com/contents/files/22395240962.pdfIn PDF document text
    • http://35ct1.com/images/ckImageFiles/files/77980019861.pdfIn PDF document text
    • http://www.elstar.ru/uploads/files/89795111657.pdfIn PDF document text
    • http://laureysnv.be/uploads/files/moweraxavoponig.pdfIn PDF document text
    • https://serka.com/serka/upload/files/42069684056.pdfIn PDF document text
    • https://chambres-hotes-aube-bleue.fr/userfiles/file/18969106319.pdfIn PDF document text
    • http://videoacceso.com/wp-content/plugins/formcraft/file-upload/server/content/files/161391429e989b---zuzenogilibu.pdfIn PDF document text
    • https://pasarantogel.com/contents/files/dosalebizo.pdfIn PDF document text
    • http://minhanh.com/files/fipotojisekupikopowew.pdfIn PDF document text
    • http://elskenecologie.nl/files/7769436759.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614847d45dc34---82008208618.pdfIn PDF document text
    • http://av72-reklama.ru/userfiles/file/1630822849867aaeec609a4260c6fe.pdfIn PDF document text
    • https://www.posluh.hr/ckfinder/userfiles/files/69073311408.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_off0000bad1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAD1 18716 bytes
SHA-256: cd08f2eecf0575177e30a82a53f67fac120674ee1424dbb5e39d4505b79b3476
font_01_sfnt_off0000eb0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010325.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10325 10952 bytes
SHA-256: 2ab62c3468bccfa0d0205f74cfef3e138bded11929feae3612529a683b6101e4