Malicious PDF — malware analysis report

Static analysis result for SHA-256 45efde5055241960…

MALICIOUS

PDF

82.3 KB Created: 2021-04-03 12:30:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 4b85ba50eb4dc2d47fa15dfdbe5dcca8 SHA-1: b797bc3d6f0e90a7fc65522caf05981dffc7800d SHA-256: 45efde5055241960c13e5b665d525da587e8f510b9e212f1ee4176bfdb2c7e3e
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many of which are hosted on disposable domains, indicating a link farm designed to distribute malicious content. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest this malicious intent. The ML classifier also flagged the PDF with high confidence. While no scripts were explicitly extracted, the presence of numerous external links points towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://jacksth.ru/award?keyword=cv+formularz+pdf PDF link annotation
    • https://rewemekekebaz.weebly.com/uploads/1/3/1/4/131406535/1380962.pdfIn PDF document text
    • https://firiwipavixura.weebly.com/uploads/1/3/1/4/131407767/zakisitosoduj-ruxarawava-gekikigixod-rubojezenalile.pdfIn PDF document text
    • https://fosogaji.weebly.com/uploads/1/3/1/4/131455903/ruvatavoxexe-gepobegazek-zowimuwik.pdfIn PDF document text
    • https://rurujopolobadez.weebly.com/uploads/1/3/4/4/134444805/2283335.pdfIn PDF document text
    • https://ruzisatof.weebly.com/uploads/1/3/4/7/134734885/jewozerarududa.pdfIn PDF document text
    • https://lojopozubog.weebly.com/uploads/1/3/1/6/131606756/5631341.pdfIn PDF document text
    • http://vatemuredaxusob.22web.org/aditya_hrudayam_stotram_in_malayalam.pdfIn PDF document text
    • https://xuxixoxeniti.weebly.com/uploads/1/3/4/5/134585484/134acf3e0a8.pdfIn PDF document text
    • http://natezaka.iblogger.org/kevaxipejetaniduj.pdfIn PDF document text
    • https://lusimijibujadex.weebly.com/uploads/1/3/4/6/134677052/5698389.pdfIn PDF document text
    • http://disupata.iblogger.org/55544020507.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xenavak.rf.gd/zodarujowazo.pdfIn PDF document text
    • https://s3.amazonaws.com/welanisowari/20575740496.pdfIn PDF document text
    • https://75edee45-cd08-43cb-a752-0c33e5c2343f.filesusr.com/ugd/a7c173_32e1903b8d4a4552bb772a636003befa.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/toguvaju/norton_antivirus_for_mobile_phones_free.pdfIn PDF document text
    • https://ce322291-b3da-4cc2-ae0f-523e25daec44.filesusr.com/ugd/4530da_d2637b4b837f4fb09dc641582c7c542b.pdf?index=trueIn PDF document text
    • https://21c505bb-01ca-4817-a549-4ed1ebba5040.filesusr.com/ugd/7d7105_d00030bb7aa248ffa31a4e9452d8e073.pdf?index=trueIn PDF document text
    • http://lumugexov.rf.gd/72745680547.pdfIn PDF document text
    • https://71a5d838-4e22-4830-8da1-7955ec3365f5.filesusr.com/ugd/f2f43e_927b72e3630047daa9549c5ec7e615d1.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xutomoxu/introduction_to_psychology_course_objectives.pdfIn PDF document text
    • https://b7e73dfe-ad35-4791-b4f7-7500f5b7882c.filesusr.com/ugd/bc79a4_21e039cada464034a5b64788c0391207.pdf?index=trueIn PDF document text
    • https://f200304d-316b-45a9-b05c-680123ec6d1a.filesusr.com/ugd/aad1a2_6cb7ce93508a4c28bd165a395c180c0a.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/muwomapotumugi/giwanorik.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_off000103b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B6 5024 bytes
SHA-256: 3f5b7fc1d31f2e7e202c46a2bf821d8df5033b891c93fdcc8b77f62ffd01dc7e
font_01_sfnt_off000114c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114C4 11984 bytes
SHA-256: 2dbf6e1f27568d7b033c584f4d7f41288ff35c63970534f3de0bf33447c52203