Malicious PDF — malware analysis report

Static analysis result for SHA-256 21134d4e8945a9ca…

MALICIOUS

PDF

74.9 KB Created: 2021-05-30 17:45:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 119c77368b95c3014653fa19bdedcbb1 SHA-1: 1e5dc9757e18e7a059d95a7c421caf2dea540227 SHA-256: 21134d4e8945a9cabbf41427e29f21114b03fe457e9c5b964965653fea3728ae
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to other PDF documents, suggesting a link farm or phishing attempt. The ML classifier and ClamAV detection strongly indicate maliciousness. The embedded URLs are likely used to redirect users to malicious sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://resalured.ru/123?utm_term=indefinite+pronouns+spanish+worksheet
    • https://jafusakivamo.weebly.com/uploads/1/3/0/7/130739280/vujununiluviditeg.pdf
    • https://cdn-cms.f-static.net/uploads/4402488/normal_601a61945fec9.pdf
    • https://jumuvive.weebly.com/uploads/1/3/0/7/130776409/vilifini.pdf
    • https://static.s123-cdn-static.com/uploads/4450517/normal_5fcbde43c5390.pdf
    • https://xogepojofaridel.weebly.com/uploads/1/3/2/7/132741214/0ca41c8d9.pdf
    • https://kenopawubiwo.weebly.com/uploads/1/3/4/4/134459696/zalukodukazub.pdf
    • https://jowidirususonin.weebly.com/uploads/1/3/0/7/130775515/wolatinag.pdf
    • https://bubokadorododu.weebly.com/uploads/1/3/4/7/134758236/7eab768fb69d1.pdf
    • https://cdn-cms.f-static.net/uploads/4369309/normal_605e0a5640d66.pdf
    • https://cdn-cms.f-static.net/uploads/4503692/normal_5fe6510e8e2b7.pdf
    • https://fapufeloku.weebly.com/uploads/1/3/1/0/131071019/nunipezazidilesape.pdf
    • https://cdn-cms.f-static.net/uploads/4405185/normal_601f3719f0335.pdf
    • https://cdn-cms.f-static.net/uploads/4459628/normal_60191b1a68604.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/e083771a-5a0c-4042-9ee7-f9d7fff84be4/ms_word_document_password_recovery_online_free.pdf
    • https://uploads.strikinglycdn.com/files/c75efcd9-df94-4e3a-b0bd-f9610730d807/poulan_pro_pp4218avx_carb_adjustment.pdf
    • https://uploads.strikinglycdn.com/files/69bfb244-e207-4bff-a3a8-ce54b269361e/moxas.pdf
    • https://uploads.strikinglycdn.com/files/a195b653-ba1a-4364-aa91-14320bef37ca/42575299197.pdf
    • https://uploads.strikinglycdn.com/files/d7eafa30-b696-4082-9912-903438eb4e1d/gumavoronow.pdf
    • https://uploads.strikinglycdn.com/files/c4b687ef-7f00-4439-a95c-dbc271a177ba/2562817563.pdf
    • https://uploads.strikinglycdn.com/files/9be70f15-6b4e-4d0a-a2dc-17832b834135/jamobi.pdf
    • https://uploads.strikinglycdn.com/files/1210bcb4-0c03-41ea-8a3a-a43065eeafaa/jack_frost_the_end_becomes_the_beginning.pdf
    • https://uploads.strikinglycdn.com/files/413cdf0b-176f-411f-8513-b47cda01e46a/the_bell_jar_quick_summary.pdf
    • https://uploads.strikinglycdn.com/files/f413bb98-5047-4da9-8c1a-3508551acbc8/crown_him_with_many_crowns_chords_in_g.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e5a7.bin
18446316ec366180d19e02d0dd7acfe79342287ae95a4553dccade1209692109
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5A7 5188 bytes
font_01_sfnt_off0000f760.bin
6976a5afa42e277e7bc9137f267d10a2f0151357c467638ca5e51dd7b148e283
pdf-font-stream PDF embedded font (sfnt) at offset 0xF760 11500 bytes