Malicious PDF — malware analysis report

Static analysis result for SHA-256 44a6a8563d8876ee…

MALICIOUS

PDF

77.4 KB Created: 2021-06-12 11:49:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 9b74d461e15506a5b036fd4936e95993 SHA-1: 6aed478e61ed02eafb322333af230aaa219e1449 SHA-256: 44a6a8563d8876ee4d1f73aefed7c606c3c35ee5d4967c977854bdb22741775b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links, as indicated by the PDF_SEO_LINK_FARM heuristic. One of the primary external URIs points to 'synerhu.ru', suggesting a potential phishing or malicious content distribution vector. The ClamAV detection and ML classifier further support its malicious nature, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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/pbw?utm_term=ring+ring+ringtone+download
    • https://static.s123-cdn-static-d.com/uploads/4370542/normal_60b3b8b16f135.pdf
    • https://static.s123-cdn-static.com/uploads/4368477/normal_5ff165c968941.pdf
    • https://cdn-cms.f-static.net/uploads/4379969/normal_601b27dfefaaa.pdf
    • https://cdn-cms.f-static.net/uploads/4420432/normal_60bebe4f87719.pdf
    • https://static.s123-cdn-static.com/uploads/4502268/normal_5fe3823d66150.pdf
    • https://cdn-cms.f-static.net/uploads/4409840/normal_601cfe795649a.pdf
    • https://cdn-cms.f-static.net/uploads/4369491/normal_5fd6c82dea6bb.pdf
    • https://cdn-cms.f-static.net/uploads/4470228/normal_600af0d903348.pdf
    • https://cdn-cms.f-static.net/uploads/4447626/normal_605ad57a99a8b.pdf
    • https://tefuledajejus.weebly.com/uploads/1/3/1/4/131437322/gilosuzabax.pdf
    • https://static.s123-cdn-static-d.com/uploads/4425515/normal_60b02ea9ccb15.pdf
    • https://sotokogel.weebly.com/uploads/1/3/4/2/134266154/luvemu.pdf
    • https://cdn-cms.f-static.net/uploads/4478968/normal_6049c70ba490a.pdf
    • https://cdn-cms.f-static.net/uploads/4450046/normal_60bf696da3537.pdf
    • https://cdn-cms.f-static.net/uploads/4369917/normal_601ef066d09f5.pdf
    • https://cdn-cms.f-static.net/uploads/4471479/normal_602e095f22326.pdf
    • https://lefagetali.weebly.com/uploads/1/3/2/3/132302894/lamivave.pdf
    • https://wekubobezug.weebly.com/uploads/1/3/1/3/131383536/1acfda87.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://bogomosimu.pbworks.com/f/tojelumozusanitemebafikeg.pdf
    • https://uploads.strikinglycdn.com/files/02a11c9a-cce1-4fea-a8ad-b34dbef45fa0/kaplan_anatomy_coloring_book_5th_edition.pdf
    • https://uploads.strikinglycdn.com/files/4bbc0af3-bd8e-4ca1-a538-a15c50e9b875/pidifogojokikir.pdf
    • https://uploads.strikinglycdn.com/files/96f82094-2f2e-4331-aa45-54419ca5ae31/28022881791.pdf
    • http://goxuluk.pbworks.com/w/file/fetch/145125591/felebewesigino.pdf
    • https://uploads.strikinglycdn.com/files/e0a875fd-0a8a-4b65-89d8-9e8aa85e74d6/fedex_customer_service_jobs_memphis_tn.pdf
    • http://namebitepu.pbworks.com/w/file/fetch/145045950/icloud_unlock_deluxe_free_download_full_version.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f2cd.bin
d57ae524f1e73053216465b165aa9dda28e63446c3e666b39bc16f79345aaa37
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2CD 4916 bytes
font_01_sfnt_off000103aa.bin
728e618444643c6a18b21a5600485a5256e7983f0b13f2068cdf6d36bf6e2392
pdf-font-stream PDF embedded font (sfnt) at offset 0x103AA 10616 bytes