Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a03f188b9d727eb…

MALICIOUS

PDF

114.2 KB Created: 2021-08-11 20:31:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: c826a9a083b0f76dadbd09332ad40029 SHA-1: 28d24e8bafb619e98adc602bcff2593ea366e3e8 SHA-256: 8a03f188b9d727eb3f3fd7e9a2d94cc92ac7cfd20b665cfbff87af4911104fa2
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous links pointing to compromised WordPress sites and other domains, suggesting an attempt to redirect users to malicious content or phishing pages. The presence of multiple external URIs and link farm characteristics strongly supports a malicious link-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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 http://dulichtantai.com/files/uploaded/files/39265396335.pdf In PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/16090960242677---70434286475.pdfIn PDF document text
    • https://www.qlsny.com/wp-content/plugins/super-forms/uploads/php/files/10aa60a333263be8151d85cbcaa1ce00/76873615981.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d242d681a80---nubenivetasexe.pdfIn PDF document text
    • http://puzynowska-kancelaria.com/userfiles/file/15463730172.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/9bg99kibb8quk33vu6vakegef0/woleranabowiru.pdfIn PDF document text
    • https://evermoral.hk/upload/file/1626377909.pdfIn PDF document text
    • https://jnvhardoi.org/ckfinder/userfiles/files/93552331010.pdfIn PDF document text
    • https://tekartltd.com/upload/files/40958878985.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608357fd43665---44697238213.pdfIn PDF document text
    • https://cape-electronics.com/media/file/10426855305.pdfIn PDF document text
    • http://baodieptailor.com/uploads/2021-06-19/images/files/16753780039.pdfIn PDF document text
    • http://slp72.com/clients/7/7b/7b902bee17765b19ebdde6030f24742d/File/50235698527.pdfIn PDF document text
    • https://sealand-pptc.com/userfiles/file/remigijo.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dc7544ef27---69513176600.pdfIn PDF document text
    • http://alianzablue.com/aym_image/files/3781708167.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name//files/pisosejurinefuluva.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/ab0a466be3130c68c0c16b694ec3c5aa/86782085501.pdfIn PDF document text
    • http://sunarfactory.com/userfiles/files/femikapizarutelaken.pdfIn PDF document text
    • http://0930actress.com/files/files/filutisij.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/f9h3uu527a3t5cavrq1soapksg/69610653354.pdfIn PDF document text
    • https://palcev.ru/userfiles/file/38549152921.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=research+methodology+objective+questions+with+answers+pdfPDF 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_off000159c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x159C4 11896 bytes
SHA-256: a8405a25895bf3023cdfb63f80caee767db354241e53ed351fe21d2fe04040fa
font_01_sfnt_off00017579.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17579 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00018d8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18D8B 16912 bytes
SHA-256: 4c85c7c4fab276f673f863655f1c102797ef14047d939c292a6930add44144b3