Malicious PDF — malware analysis report

Static analysis result for SHA-256 b255dbeba797980f…

MALICIOUS

PDF

77.0 KB Created: 2021-04-06 05:53:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 00192e9794e4f18cd961052bd3b719be SHA-1: b17136e880ef773d8856ce278307a08bee65d3dd SHA-256: b255dbeba797980f6befee7b5b8057b2dce4539049a6937143150eb4a0b1ffc7
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable domains, indicating a link farm designed to drive traffic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous external URIs suggest it's designed to redirect users to potentially harmful content.

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://jacksth.ru/award?keyword=pdf+viewer+no+toolbar PDF link annotation
    • http://secureappeal.com/conjugate_acid_base_pair_worksheet_19-_2wvraj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477921/normal_5fe63603784fc.pdfIn PDF document text
    • http://sosed.market/96273952937wq5vi.pdfIn PDF document text
    • http://reetodo.online/xupeferodipenijipuk7z8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376404/normal_5fdc0a5087a1a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483604/normal_6047c75358dff.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423442/normal_601604b4e3c60.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420019/normal_5fde2272bc549.pdfIn PDF document text
    • http://consumer-data-protection-bureau.com/bidapovedarel5r7dj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478134/normal_6041b512a384d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4447253/normal_5ff93a63a7288.pdfIn PDF document text
    • http://mimivamefigupe.sportsontheweb.net/difference_between_capstan_and_turret_lathe.pdfIn PDF document text
    • http://8bitbeardsco.com/how_to_setup_stc_1000luzks.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374379/normal_603607c419243.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://5cbbff6b-7c47-4fbb-abda-9de5069fbc88.filesusr.com/ugd/1a89c8_3c9fe511ed2f43d792a14abf9b5a288c.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xidazeze/pugitijagino.pdfIn PDF document text
    • https://2d130471-2a64-48ba-87cf-8f1e86c6acad.filesusr.com/ugd/9c43ec_0d5987f594c74c3cbd8cb7d329722260.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zurovajij/how_to_remove_a_carburetor_from_a_snowblower.pdfIn PDF document text
    • http://wugerubuvugox.myartsonline.com/zuredasedegopagudu.pdfIn PDF document text
    • https://42172c5f-463d-425f-bc49-3536d5e9b788.filesusr.com/ugd/3e9aab_793edb5a4d05452aa2423b54c352ea6a.pdf?index=trueIn 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_off0000e5ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5AB 5016 bytes
SHA-256: ab2274d4b7ea5fca804c7fedea3a5ddfb5cfa3aa4cae8b5bf15a22ad19d38d60
font_01_sfnt_off0000f6d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6D8 1936 bytes
SHA-256: cf50d13c5c21d2e34fba0d9dd21119d4839fc35fdaebfe62cbacf51850cc328d
font_02_sfnt_off00010017.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10017 11244 bytes
SHA-256: 69bf0964dddaafb1987df4c10caddf5bf8cfff27a41cea345b7a7c165b764e61