Malicious PDF — malware analysis report

Static analysis result for SHA-256 87f41774ac5e675c…

MALICIOUS

PDF

82.7 KB Created: 2021-05-24 04:43:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 41a49154dc19074531601b504210df4b SHA-1: a829cfb07d6d2e0da4b1b4ac5bfda89b4139ab85 SHA-256: 87f41774ac5e675c0bb2eae2679a5c69f58d5da4e5d13e1413e674cc4b901ec3
186 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains a significant number of external links, many pointing to disposable hosting services, suggesting a link farm or phishing operation. The primary URL, 'https://baarspo.ru/strik?utm_term=how+to+sell+pre+market+thinkorswim', indicates a potential lure related to financial trading, possibly a scam. No scripts were extracted, but the PDF structure itself facilitates the attack by hosting numerous redirectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://baarspo.ru/strik?utm_term=how+to+sell+pre+market+thinkorswim PDF link annotation
    • https://mejiwixibunoxu.weebly.com/uploads/1/3/4/4/134402053/wuxewuje-tutofurizisijiz-vogutejadimozi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489596/normal_6028b7bfc5adc.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4416929/normal_5ff184dabb499.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393369/normal_603a0db8b38a7.pdfIn PDF document text
    • https://kowalarezanir.weebly.com/uploads/1/3/1/4/131438161/faweped-zakuriguv-kegonugosinud-xiwuru.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4411921/normal_600073e5aa0ff.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413242/normal_60546a7cc6874.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417023/normal_601139b9eb1b9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4382953/normal_5fe3c785857cc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369771/normal_604cc1cb446b7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4527108/normal_606ca6526638a.pdfIn PDF document text
    • https://gagumosesixibo.weebly.com/uploads/1/3/4/0/134018544/3153404.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4473638/normal_5ffe4646bdd60.pdfIn PDF document text
    • https://xizirasifeda.weebly.com/uploads/1/3/4/3/134344010/3013915.pdfIn PDF document text
    • https://nofitipofawotuj.weebly.com/uploads/1/3/4/0/134012335/suxumexoga-suwetetunu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383300/normal_60659055758dd.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/b8a98a33-bb8a-4db2-9fca-3d3ae896b2ca/how_to_unlock_amana_washing_machine_door.pdfIn PDF document text
    • https://s3.amazonaws.com/radubozufiwo/pavotikojezenitatekuli.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bc2c8242-88d7-4301-8835-6c535bb9ce6e/renogiriwakigukuj.pdfIn PDF document text
    • https://s3.amazonaws.com/rimejiguvif/the_odyssey_book_13_questions_and_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cb031bb0-ca68-4da0-87ca-49378c964258/linejazik.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/364ef766-3c7b-491e-8b83-2cbc82b22799/bowflex_pr3000_home_gym_at_amazon.pdfIn PDF document text
    • https://s3.amazonaws.com/loranoduzuja/crossword_answer_for_excessively_sentimental.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5735ce79-b14f-42d7-9751-4b288816a1bf/sullivan_precalculus_10th_edition_solutions.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_off0001046b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1046B 5176 bytes
SHA-256: 63c202c92add6eb06e7aafc560029882ad878e76bfbd0095ce1646196c730267
font_01_sfnt_off000115e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115E2 11508 bytes
SHA-256: 3bcb314e8fa403a9264532b57917c7889298b191a2374cadf1ecc4b17d726b61