Malicious PDF — malware analysis report

Static analysis result for SHA-256 161d296e19122c48…

MALICIOUS

PDF

67.1 KB Created: 2021-03-10 09:31:37 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 8372cd1e05892d554b04e4f24d25be31 SHA-1: 21424eaf6a3d9e1fe713ea5433556dbc1486ce22 SHA-256: 161d296e19122c48140590848eea9e4a187aff15d4b8869ad5b96fbcfe4e7426
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 hosting, suggesting a link farm designed to drive traffic to potentially malicious sites. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' indicate this behavior. The embedded URL 'https://nipisod.ru/123?utm_term=convert+scanned+pdf+to+word+ocr+free' further supports the lure of a free tool, likely a pretext for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nipisod.ru/123?utm_term=convert+scanned+pdf+to+word+ocr+free PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4382790/normal_6017c36f454c4.pdfIn PDF document text
    • https://xatuguje.weebly.com/uploads/1/3/1/8/131856293/kujepoxitejimefa.pdfIn PDF document text
    • https://bakogala.weebly.com/uploads/1/3/1/3/131384254/41b81bd59865ff7.pdfIn PDF document text
    • https://kafaziwe.weebly.com/uploads/1/3/1/0/131070109/foluwileg.pdfIn PDF document text
    • https://sapuzexa.weebly.com/uploads/1/3/5/3/135348006/4976660.pdfIn PDF document text
    • https://pexiseziburenof.weebly.com/uploads/1/3/4/6/134685472/xukonuxoninok-mamaterunus-fexejafunugudu.pdfIn PDF document text
    • https://funogefoxareso.weebly.com/uploads/1/3/4/0/134041001/nemokewedesed.pdfIn PDF document text
    • https://goreduve.weebly.com/uploads/1/3/2/7/132740848/9426827.pdfIn PDF document text
    • https://saxarewuvopa.weebly.com/uploads/1/3/4/8/134855039/joxosogin-guzesaxu-kojawe-tujafedusonol.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467003/normal_5ff1564c56aa2.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://61090d85-22e6-4724-b969-52a17785150c.filesusr.com/ugd/952c2e_cbbe517b092942fd91e53c7a99534a1b.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/libusamagowuvo/xixefabutojowaseguna.pdfIn PDF document text
    • https://bcd7deca-fd5d-492b-a220-d373ca515bc9.filesusr.com/ugd/12f4eb_2d5edff1b00c4ba3a3fb749c74300ef7.pdf?index=trueIn PDF document text
    • https://6d5fec37-5936-4ae8-8938-03a86e982f09.filesusr.com/ugd/d4da64_71f141d0894847309f1f2b479bbe3521.pdf?index=trueIn PDF document text
    • https://2a4065d7-883d-43e8-a524-7ce9aa4b4e88.filesusr.com/ugd/ccb1c6_973769ae72c245fa94ae80e19842b1b1.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/mokuwanibof/64011074390.pdfIn PDF document text
    • https://1237a3da-0b33-4890-9ba9-974507bf2590.filesusr.com/ugd/3e0cb9_9f14239164024b1383314f8753ec43d2.pdf?index=trueIn PDF document text
    • https://2e6726a7-2e78-456a-9fa1-8bc85c3b20a6.filesusr.com/ugd/76e31d_f5aac54a2d7545b9babb406f57a7fcad.pdf?index=trueIn PDF document text
    • https://9a4b5e96-23fe-4021-9525-787506808755.filesusr.com/ugd/b3318b_e2daef44510a4087b1d9540d4df26831.pdf?index=trueIn PDF document text
    • https://a9864912-ad24-422b-99f3-2d90f7703507.filesusr.com/ugd/d6af85_0cc6b746168e45c3bfea95fb745f5e4e.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB75 5176 bytes
SHA-256: 16795a4de9adcd280b8f434bf92fa9a17d94d4a3696f66d520a95758a12dbfde
font_01_sfnt_off0000dd32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD32 9948 bytes
SHA-256: cb429fc42a5b61735616a6a76d5c0ddf405d8edb3c194e2a4b386d51759cd6cb