Malicious PDF — malware analysis report

Static analysis result for SHA-256 9acf5852e2c8dc2f…

MALICIOUS

PDF

70.2 KB Created: 2021-09-30 14:31:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ccff5bbee9341041ac96068ca2ccc57b SHA-1: 03c1a87fc330bf2538f581a32120ee799da01bbe SHA-256: 9acf5852e2c8dc2f5bbd4a16bb2fbf4265ff88eadb476164a6a4bea3b743c4eb
96 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded URLs pointing to various compromised websites, suggesting it's designed to redirect users to malicious content. The ML classifier strongly indicated maliciousness, and heuristics identified it as a link farm on disposable hosting, likely intended for phishing or malware distribution. No scripts were extracted, but the sheer volume of external links is a significant indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 5

  • 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://synerhu.ru/uplcv?utm_term=chrome+web+store+auto+clicker PDF link annotation
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/16142e932d8b55---zeterimusiligaj.pdfIn PDF document text
    • http://preiss.at/upload_files/files/zitobijijo.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614d9830d0a08---66671706984.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/ivs60oe08beo34dvmrr1unikl8/pukebirejutizirowogomax.pdfIn PDF document text
    • http://proart.by/media/file/85606276437.pdfIn PDF document text
    • https://villamishkan.com/310renonew/front/images/files/xisix.pdfIn PDF document text
    • https://fibaquitaine.fr/cebatrama/userfiles/files/kitite.pdfIn PDF document text
    • http://ipoz.pl/userfiles/file/35006622384.pdfIn PDF document text
    • http://yugang360.com/upload_fck/file/2021-9-14/20210914141520220708.pdfIn PDF document text
    • http://guchen.ru/d/files/36683778915.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/962f98aad91b5649becc003bc064e1f5/jogafipizo.pdfIn PDF document text
    • https://flomogroup.com/upload/files/puxukozemidudobipujes.pdfIn PDF document text
    • https://bayihoki99.com/contents/files/vimiwukoruja.pdfIn PDF document text
    • https://vhssirimpanam.org/ckfinder/userfiles/files/62885686212.pdfIn PDF document text
    • http://alltechsro.cz/files/47236749648.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/fb4e5287f2c04df509e1720b2fbb4eb0/65816648259.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/t98rhoktmpscmkqf4jutmfrm5u/puduzekiropal.pdfIn PDF document text
    • https://aldurra.ly/images-editeur/img/file/xisapazovuwemunis.pdfIn PDF document text
    • http://tw-tms.com/uploadpic/xw/files/nivobujujatanosug.pdfIn PDF document text
    • http://szwygs.com/upload/1169032769.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_off0000ac7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC7F 10840 bytes
SHA-256: 9e40df896625e825e632e985f550a6eddb4e491b300e1ead71e941df2e46cdd9
font_01_sfnt_off0000c5a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ddb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDB7 17328 bytes
SHA-256: 54b65ea0c49d200aebf09b9b63f6f54d7eb3a06e1cd8e14926dbe5e211d4508f