Malicious PDF — malware analysis report

Static analysis result for SHA-256 b55c0ab894e0a831…

MALICIOUS

PDF

91.4 KB Created: 2021-08-10 01:43:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: aa8f5de4b3121d0f1b6ca6a7a72340c0 SHA-1: f5a22740d3ff52310043a6f4cb90be78d307d96b SHA-256: b55c0ab894e0a831017a63be39d40a6625b250285555e3873eefc37d1bd5a5c1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF contains a link farm pointing to compromised WordPress sites and disposable hosting, suggesting it's used for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are strong indicators of malicious activity, likely involving redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://ketchas.ru/uplcv?utm_term=que+son+indices+marcas+de+auditoria PDF link annotation
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/367652027ea9e33e4c9e5377fb9dc023/sagivodadidekugurapi.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/66409658975.pdfIn PDF document text
    • http://autoscuolauniversale.it/userfiles/files/kogokijulokuvalalox.pdfIn PDF document text
    • https://la-klamm.org/Files/files/97492736209.pdfIn PDF document text
    • https://tyeetomsfishing.com/userfiles/file/zuserifapiwote.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/16072dee329017---bafodifosipi.pdfIn PDF document text
    • http://xn--42-6kcdlkbomh7beggito5p.xn--p1ai/userfiles/file/rofaxatijevi.pdfIn PDF document text
    • http://gallery4walls.com/upload/editer/file/8855914668.pdfIn PDF document text
    • https://newtop-eg.com/userfiles/file/57931715206.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/ea4f5f1f2a3178cd306c0a80c5f51a12/9139018508.pdfIn PDF document text
    • https://lymfologi.se/anvandarbilder/221/files/945744669.pdfIn PDF document text
    • https://vresponse.net/userfiles/file/pasimo.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607e940815335---vakatewupijewijefog.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/4780458596.pdfIn PDF document text
    • http://usmleworkout.com/files/file/tubexenigiregudara.pdfIn PDF document text
    • http://chupanhnoithat.vn/upload/files/5867358359.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/d4fde75f9422f7d3bf403dba18931faf/57690246852.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607019c313b14---vamutex.pdfIn PDF document text
    • http://grotech.in/userfiles/file/vonixalejuduvad.pdfIn PDF document text
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/99570971445.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name//files/48061084190.pdfIn PDF document text
    • http://rcp-ranstadt.us/files/32913694363.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a07a0ac641f---47239895112.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d1d3f535ab---bagibabepirutekaj.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ea5132b44---nezowanirunenuvizu.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_off0000fed6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFED6 18224 bytes
SHA-256: 190b13e2c3cca94cc1dac97882a7f9689d34bcb7a29c87ab3cc36243896d2787
font_01_sfnt_off00012da0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DA0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000145b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x145B7 10644 bytes
SHA-256: a6df45140001a72f7bf9ad60af1dd975a3f7b0ae790aac8b2e536144b49cd1e5