Malicious PDF — malware analysis report

Static analysis result for SHA-256 acd21bcdf0b97ea5…

MALICIOUS

PDF

71.3 KB Created: 2021-01-11 17:44:56 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 69ce254b91de559dd49556d6cf00bc66 SHA-1: 1917e1341fe02f2e970c80f154abdecd76e3eac5 SHA-256: acd21bcdf0b97ea59d0f4132838bbf40cc623c496886ae983ba2c6ae99d1febc
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 pointing to other PDFs, indicative of a link farm or phishing lure. The ClamAV detection and ML classifier strongly suggest malicious intent, specifically identified as a phishing trojan. While no scripts were extracted, the PDF structure and numerous external URLs point towards an attempt to redirect users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

Heuristics 5

  • 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.
  • 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://trafficel.ru/aws?utm_term=ssc.+nic.+in+answer+key+2019+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4392661/normal_5fadc0b79a90b.pdfIn PDF document text
    • https://tavifarexup.weebly.com/uploads/1/3/4/6/134611028/3697319.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368732/normal_5f89ae9ebba59.pdfIn PDF document text
    • https://site-1166598.mozfiles.com/files/1166598/zeduvaxulinu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4452607/normal_5fd3345e668d0.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454808/normal_5fd07d8ac29cb.pdfIn PDF document text
    • https://lularufopit.weebly.com/uploads/1/3/5/3/135326527/9292934.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4479917/normal_5fc359b74b146.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/jonora/install_flash_player_for_chrome_android.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_off0000d83f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD83F 5992 bytes
SHA-256: a0ecb711c65eff7dec2711df0459402a075b0d14bc00e2cb3cc4dcd598ae0c20
font_01_sfnt_off0000ecdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECDB 10676 bytes
SHA-256: bed8d71a9cb6cd5c88d2eb2ddbc84b2ad52dbb8bf9b88f89aa0643d9608f01fa