Malicious PDF — malware analysis report

Static analysis result for SHA-256 99b5537e4959c503…

MALICIOUS

PDF

80.8 KB Created: 2021-03-31 16:35:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 1711836538e07f8777e34a2920123952 SHA-1: 0088d03f5ea75ce2bccc75b528ec9166bfe8ac32 SHA-256: 99b5537e4959c5038c3f9562fe45afa2c62617aa73cad7e1859293a32c868c56
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO spam operation. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://jumiwimov.ru/award?keyword=maharashtra+housing+society+bye+laws+2020+pdf PDF link annotation
    • https://bofazoxoniwepiv.weebly.com/uploads/1/3/4/4/134454835/7842459.pdfIn PDF document text
    • https://vesabigixovo.weebly.com/uploads/1/3/1/8/131857304/4089402.pdfIn PDF document text
    • http://rbqjkwklnd.xyz/zajenosozenirabupi4n14v.pdfIn PDF document text
    • https://sifurimunudop.weebly.com/uploads/1/3/4/3/134328932/25515b.pdfIn PDF document text
    • https://cdn.sqhk.co/pujazojiwixi/gbpibgh/tekeworelekelew.pdfIn PDF document text
    • https://cdn.sqhk.co/wubukuxivupe/uWqQigR/jurusezesanegefu.pdfIn PDF document text
    • https://cdn.sqhk.co/tabewinudeka/fm5Bhbf/fexomeranununapeti.pdfIn PDF document text
    • http://buyfastedcircle.xyz/moduxigadinuguribapifusfkh8y.pdfIn PDF document text
    • https://cdn.sqhk.co/lubigegek/rCOjbtB/registro_de_brasfoot_2019_gratis.pdfIn PDF document text
    • https://cdn.sqhk.co/bokirebi/gSJ8jfX/tennessee_titans_roster_2019_pictures.pdfIn PDF document text
    • https://cdn.sqhk.co/bepoweruga/gdhhcsI/40749771736.pdfIn PDF document text
    • http://kismykeitio.best/carlson_biological_psychology4dqfr.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/c67ed7c8-e673-4603-b609-737a438614bf/40290691056.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/75ab2f87-155c-42a7-92ac-b9963f00b60e/dutch_oven_cookbook.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ca3ca70a-7fe9-4f7d-906b-84fb65cc28ff/toshiba_dvd_vcr_combo_manual.pdfIn PDF document text
    • https://48cc712b-de5e-493e-a198-f8962849e22b.filesusr.com/ugd/d2751c_06efb56178ca49b2ac06211a6aafbc83.pdf?index=trueIn PDF document text
    • https://557345b1-98c6-442d-b460-9e357c178e5b.filesusr.com/ugd/dfb5f8_c7c933479d5546f0ae2b2e77851a1c26.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_off0000f012.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF012 5912 bytes
SHA-256: 65584eff7364fd0926f208e33499d9c47f64b80ab5d9cca626e699ef236621c5
font_01_sfnt_off0001043f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1043F 10412 bytes
SHA-256: 0ca51f14984abf2ab2e76889a9808ea787f3d4d1d72fbd429c4f0e7cb1b525e8
font_02_sfnt_off000127df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127DF 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3