Malicious PDF — malware analysis report

Static analysis result for SHA-256 a92a5f8d0e3b530f…

MALICIOUS

PDF

77.6 KB Created: 2021-06-05 10:38:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: 1ae308b3476330803500acfd4e05411e SHA-1: 53be4e2d23ac2cab577e374ec88ae37a2aef483c SHA-256: a92a5f8d0e3b530f08500d7f7f84965b930ee93abf174d20ad33cf8ded947b0e
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many of which are on disposable hosting, suggesting a link farm used to distribute malicious content or conduct phishing. The primary URL, 'https://chcial.ru/pbw?utm_term=vitalsource+bookshelf+download+books+to+pdf', is presented as a resource for downloading books, a common lure for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8071

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://chcial.ru/pbw?utm_term=vitalsource+bookshelf+download+books+to+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4473340/normal_606e45aaeaa87.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460449/normal_5fd37bff43dc6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370076/normal_6042fcb9a5526.pdfIn PDF document text
    • https://zewakifu.weebly.com/uploads/1/3/0/7/130740590/3bd37bbe2.pdfIn PDF document text
    • https://kikeletiwemuk.weebly.com/uploads/1/3/4/6/134671512/8110113.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413867/normal_5fc91bb7357b2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368219/normal_6029b0b053e46.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/d4017cd6-ac00-46e9-b21c-aa06b9d66b77/what_was_the_main_difference_between_calvinism_and_lutheranism_group_of_answer_choices.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/63159f66-8afe-4f7a-a8cb-2ddd01633555/lugazu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7e35346f-021e-4119-a133-ce54af1e162a/23102044435.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fd4af1b1-a1d6-4d9a-b5f8-d67913e9adb9/30688831158.pdfIn PDF document text
    • http://gibabug.pbworks.com/w/file/fetch/144575145/39980994217.pdfIn PDF document text
    • http://gutupum.pbworks.com/w/file/fetch/144653184/what_gaba_receptors_do.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/74eab0ff-d24a-490c-b538-fd0026586699/55432242024.pdfIn PDF document text
    • http://ravowibosu.pbworks.com/w/file/fetch/144612249/assassins_creed_unity_free_download_for_pc_highly_compressed.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c89a5b1b-eefa-43cc-a0a5-282a929a1e2c/lubabuve.pdfIn PDF document text
    • http://poguvovuk.pbworks.com/f/66960425135.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/01bb8d61-5988-4100-9025-a779bc9ea1e7/82676443374.pdfIn PDF document text
    • http://jotoxipigi.pbworks.com/w/file/fetch/144463080/muxesutekutug.pdfIn PDF document text
    • http://xuwedateredu.pbworks.com/w/file/fetch/144592149/how_do_i_use_my_roku_if_i_lost_my_remote.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5c4f673f-be4d-415c-92ef-0d33bb50192a/90106707864.pdfIn PDF document text
    • http://kepigiwup.pbworks.com/w/file/fetch/144612741/1996_yamaha_big_bear_350_oil_change.pdfIn 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_off0000f07d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF07D 5384 bytes
SHA-256: bee30659c65f65b39bcdd9a595180623e254e5f9f7f7275f6b81c01cc9ea4067
font_01_sfnt_off000102cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102CC 11108 bytes
SHA-256: 8b94308a7fb69b25b45b101a2dd46469f29ba72dfcd7473e2a5f704e25a2d045
font_02_sfnt_off000128dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128DC 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c