Malicious PDF — malware analysis report

Static analysis result for SHA-256 51459c1d66d3899c…

MALICIOUS

PDF

81.0 KB Created: 2021-05-30 14:18:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 748e3a7471922631f30f3531959e1142 SHA-1: 20bdd1ec951178ef100841de2f118af596e6ab45 SHA-256: 51459c1d66d3899c044e63371db5359668e1d39306312d67856aebd4a96027bf
134 Risk Score

Malware Insights

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

The PDF document, disguised as educational material, contains numerous embedded links to external websites, many of which are hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of external URIs and the 'link farm' heuristic suggest the document is designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://zajinet.ru/123?utm_term=fractions+worksheets+year+5+uk PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4413374/normal_5ff55809d3fbf.pdfIn PDF document text
    • https://dexajuvado.weebly.com/uploads/1/3/4/4/134470202/bebuvofukolajamene.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416149/normal_602eeeda9148d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465914/normal_606966cd0eeb4.pdfIn PDF document text
    • https://molilavavabofu.weebly.com/uploads/1/3/5/9/135989114/wulogodeguzakif.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4472773/normal_6065c9ceb1fe2.pdfIn PDF document text
    • https://susopusamug.weebly.com/uploads/1/3/4/3/134336197/eca9132ab6381.pdfIn PDF document text
    • https://xedububedopo.weebly.com/uploads/1/3/0/7/130740082/6298216.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376359/normal_6043dc423694c.pdfIn PDF document text
    • https://tesokumerapaj.weebly.com/uploads/1/3/4/5/134522001/48994.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459054/normal_601a814c459e0.pdfIn PDF document text
    • https://redunexodozik.weebly.com/uploads/1/3/0/8/130814050/6749237.pdfIn PDF document text
    • https://jujizifij.weebly.com/uploads/1/3/4/3/134309807/922f44c.pdfIn PDF document text
    • https://fawukudaboguris.weebly.com/uploads/1/3/4/3/134353338/jegejigetaj.pdfIn PDF document text
    • https://bejejedagaf.weebly.com/uploads/1/3/4/8/134862385/borojujaw_gufavojiwoni_nigebudepo_jelemotadu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457849/normal_60672198c974e.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://uploads.strikinglycdn.com/files/02d6eca5-c342-442d-94ed-3cd3ea9ebace/is_disneyland_in_anaheim_open_to_the_public.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/052aff9e-b147-4844-bff6-f3729bdff172/hp_6700_premium_ink_system_failure.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6f7f6b20-54c8-4c40-9d32-437e9968d7d2/daniels_running_formula_reddit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7da177bb-2819-4476-9d52-58398423d9cf/the_royal_standard_of_england_buckinghamshire.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/31167ae5-219d-439c-a527-3f8d3907695e/adventures_of_tom_sawyer_example_book_report.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9b70c624-85d1-4ca4-897b-b4bf635f3d85/armstrong_air_gas_furnace_troubleshooting.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b7beca9d-0ad1-4e92-b657-d95d3aea5271/xasijulelenuzopabir.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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f2dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DD 5076 bytes
SHA-256: 3dda43a12af9d1f04857e01adc08a3927c8004fed89af66c2bc8a5a0e7df4965
font_01_sfnt_off00010429.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10429 10572 bytes
SHA-256: c3b81bd3ff6124a201c6ca490f1772fe41876ad349662cc4f2d0f26bfa716d6a
font_02_sfnt_off0001282f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1282F 4324 bytes
SHA-256: 7f6049e5011acf0e8581793f2bc2bb947aac2929fdb77abc318b2a6155c1ef71