Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1a15c6a53ff76d1…

MALICIOUS

PDF

107.0 KB Created: 2021-03-11 17:47:59 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 9ec3512a3d14e2beb096c065224ab584 SHA-1: 74ab65337389b4833f028bbcabad5c9070c09675 SHA-256: a1a15c6a53ff76d16600c674c292b3757cc73bfc4b7775c0b5b0e9c9df9e301b
126 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier with high confidence. It contains numerous embedded URLs, with one specifically pointing to a 'medical certificate form' lure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for multiple links, suggesting a phishing or malware distribution scheme. No scripts were extracted, but the presence of external URIs and the overall detection profile strongly suggest a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://kuzutuzo.ru/123?utm_term=medical+certificate+form+for+brta+driving+licence PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4501789/normal_5ffbd9715e85d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450724/normal_5fecfe14c21cd.pdfIn PDF document text
    • http://carbags.site/jomogafasepobigisen1zxf.pdfIn PDF document text
    • http://5gusevshop.space/mlb_shop_returns_canada9b72t.pdfIn PDF document text
    • http://mebelrostov.ru/bajakq0nqh.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4447278/normal_5feaf9381f606.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376101/normal_601ae02f24f34.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384822/normal_5fdab239dddf5.pdfIn PDF document text
    • http://wofijolusiga.iblogger.org/cg_bsc_nursing_2019_answer_key.pdfIn PDF document text
    • http://morujonimavop.22web.org/mejaduxazezaxibe.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://48cc712b-de5e-493e-a198-f8962849e22b.filesusr.com/ugd/d2751c_8503916b5c5a4109bd8f5dfe914e9feb.pdf?index=trueIn PDF document text
    • https://d5fd0048-bb8d-45a1-ba21-28d1cb0b7162.filesusr.com/ugd/5e8de6_2a5d0b77525e432bacf1ddbb91818a5d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/2c1fbfd7-3505-452f-83b2-35703a567b42/42315424799.pdfIn PDF document text
    • http://winibosekuzel.epizy.com/wiwimitive.pdfIn PDF document text
    • https://2a403a33-5f6e-4534-96f9-742aa7325afc.filesusr.com/ugd/d2da83_b026d37c587549e093ee05199f89bc22.pdf?index=trueIn PDF document text
    • https://8d90b851-447f-4cfc-ac95-1e867b71b983.filesusr.com/ugd/b371d9_294853416d9c4d2d902b3eec7216dd61.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/eec9481d-6cc9-4505-bc8f-72c0093978ce/introduction_to_mechanics_kleppner.pdfIn PDF document text
    • http://kelawezup.rf.gd/kuta_software_algebra_1_worksheet_factoring_trinomials.pdfIn PDF document text
    • https://bf808793-8b46-4c54-8b11-319763181fa0.filesusr.com/ugd/0d018b_c9ad6f92a2f249cf9f40fc7cdac6d336.pdf?index=trueIn PDF document text
    • http://pegewolonu.rf.gd/que_es_dibujo_tecnico_urbanistico.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://scripts.sil.org/OFLIn PDF document text
    • http://www.geocities.com/mitra_anirban/hobbies.htmGNUIn PDF document text
    • http://www.gnu.org/copyleft/gpl.htmRegularIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012ed8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ED8 5156 bytes
SHA-256: 4c97c7a639e3350e84079c01f8b3a98ffc983a4a8e522540685ddf2e2dc0339b
font_01_sfnt_off0001404a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1404A 13632 bytes
SHA-256: eb5536f50e751148e3ccb82e7170b2daf8d517862fa8d149b48d85acd486e400
font_02_sfnt_off000169c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x169C5 10488 bytes
SHA-256: e9d76dcffb24686b985313c47f985f21caea250eca9cf89c1c1acfe04fb1ed5e
font_03_sfnt_off00018d92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18D92 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3