Malicious PDF — malware analysis report

Static analysis result for SHA-256 cc6e4e31e878aa41…

MALICIOUS

PDF

80.1 KB Created: 2021-04-30 07:31:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-04
MD5: 4b341356211054d9a0288d1d0caa13e6 SHA-1: a379f41d0716d10fae7bb17d1f5bef75d466e104 SHA-256: cc6e4e31e878aa41001cd61ecaf92af14a9c431f22ac10d605f17872d4aa6aaf
156 Risk Score

Malware Insights

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

The 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 many URLs pointing to compromised CMS upload directories. The document body, though heavily obfuscated, contains references to 'Android manager to sd card' and 'wkhtmltopdf', suggesting a lure for potentially unwanted applications or further malicious downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16083bae60e043---fujolozuxulibi.pdf In PDF document text
    • http://charivne.info/images/file/jiditotidezive.pdfIn PDF document text
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160702d2663719---gisiromuro.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/0e0cae24fc20e62fd0636e60e712accc/78060097636.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160719d1798eb3---bufuzixomuxamozezen.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16081bf8e55cd8---10680151245.pdfIn PDF document text
    • https://absolut-fit-and-dance.de/wp-content/plugins/super-forms/uploads/php/files/6pg98c15107tkm5vcb4e6t3vfi/5465432698.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/08dsssg8s5cd52tpn7kojtnhv3/sukudasuvudaroxu.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/35f1eeef4c46561ee613d2bb334181a3/62335813926.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/160828a7cdf7fd---xaliwudunutigenowewob.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078e379855dc---laboxosakokit.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/16083b979df6c9---josasenotuwijerule.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607814296ddab---kapidaxuper.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088013c14cf9---vogerivovupojafeladubizo.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/912381586b2d3964be0e47aa0c4fcea5/86928806461.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/db0ccd535252dfb307d322782e625bf4/dalozuzuwogikumejas.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=android++manager+to+sd+cardPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f9bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9BB 5216 bytes
SHA-256: 0c6b7723d9d5095c5d3e690b46396e8a693e374557e878453f094195144d1d28
font_01_sfnt_off00010b5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B5E 11620 bytes
SHA-256: 75f228fb50ed03bda864ee7cb71dddcc5a1797a47504a8faadaa84765bd4e5ff