Malicious PDF — malware analysis report

Static analysis result for SHA-256 76f52c7fd7672399…

MALICIOUS

PDF

71.8 KB Created: 2021-06-08 02:03:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: e23bbadcc39e4dd73ec796214d2f6c32 SHA-1: 04a4b8836747edcdfed4e74a8ab1d60fe6a59ad4 SHA-256: 76f52c7fd7672399a5521f66368a77a4b65080249e7bf6202d59bfe6f6c2f3f0
186 Risk Score

Malware Insights

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

The PDF file contains a mass external link farm, with many links pointing to disposable hosting and utilizing UTM parameters, indicating a phishing or SEO spam campaign. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to malicious websites or phishing pages. The document body, though heavily obfuscated, contains text related to search queries, reinforcing the lure tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 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.
  • 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://krisoc.ru/pbw?utm_term=what+does+jackrabbit+mean+sexually PDF link annotation
    • https://ridimejaxokixis.weebly.com/uploads/1/3/5/3/135340331/8333059.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4503787/normal_60379ea1a3f7b.pdfIn PDF document text
    • https://xopaluwejur.weebly.com/uploads/1/3/1/8/131857284/puvurolerofim-piraturuge-xilex.pdfIn PDF document text
    • https://xunujilitaga.weebly.com/uploads/1/3/5/3/135315779/vowodopetoz.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419650/normal_602ce09121117.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418383/normal_604d4055dac59.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501054/normal_603ccec67b79b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4464082/normal_6008185a9c67a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417406/normal_60ba0aa92bfe5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420018/normal_600dad26e361b.pdfIn PDF document text
    • https://wijekuwonud.weebly.com/uploads/1/3/4/6/134645716/medure.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465402/normal_6046afad63031.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4466408/normal_5feed5ab156a6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446263/normal_601b9a175273c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://jubujefaj.pbworks.com/f/zibixorupubigomazur.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/65337e4a-b923-442c-a50f-6fd0585ce3c9/what_is_the_freudian_dream_theory.pdfIn PDF document text
    • http://giwupiraride.pbworks.com/w/file/fetch/144771219/pixel_car_racer_engine_mod_apk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a55631b4-dc58-4415-b517-24a52c790f32/2015_ap_english_language_and_composition.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/92815ca5-85c6-4240-a56a-00d0aeb45fd7/ropozuxunedemuwaromij.pdfIn PDF document text
    • http://xelivolofuso.pbworks.com/w/file/fetch/144533565/xuxifewinovowawugazimi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e9f05c60-395c-48ec-837f-db905e8ef62b/duraxorozatixoloxegefo.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC7C 5640 bytes
SHA-256: 71f84d3f6497e823612e35f66e5f3259dd38185a32b02c2ca743938b512baa43
font_01_sfnt_off0000efa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA0 10060 bytes
SHA-256: e901c33d5df12d432550e665a1239947ff49ef9c276f7f50ef37da1a79d6aa7f