Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a23520e438db929…

MALICIOUS

PDF

71.7 KB Created: 2021-01-06 11:44:58 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8421d657b3226f2f073365dbdcb2764f SHA-1: 7bb9bdd5fd2cd1f1711d0681fcd07a330c1383f4 SHA-256: 1a23520e438db9299648f5ea0f28e8f48bef4bd9ed424ac83364d83ea000eca0
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm of external PDFs and an embedded URI pointing to a suspicious domain, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the presence of embedded URIs and the nature of the heuristics suggest an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://traffnew.ru/123?utm_term=lenel+lnl-x2220+installation+manual
    • https://static.s123-cdn-static.com/uploads/4420924/normal_5fc759ce4130c.pdf
    • https://dovogejeromew.weebly.com/uploads/1/3/4/6/134666082/wakota.pdf
    • https://cdn-cms.f-static.net/uploads/4370054/normal_5f880c615f017.pdf
    • https://cdn-cms.f-static.net/uploads/4379229/normal_5f9faf28f30cb.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://s3.amazonaws.com/poresi/97579514288.pdf
    • https://s3.amazonaws.com/bisazabe/animated_ppt_slides_free.pdf
    • https://s3.amazonaws.com/gomaxod/outlook_multiple_emails.pdf
    • https://s3.amazonaws.com/zomuzigo/asus_max_pro_m1_android_10_update.pdf
    • https://uploads.strikinglycdn.com/files/2cdcd5a4-fec0-4cd4-a99c-08657b18ef97/13587785947.pdf
    • https://s3.amazonaws.com/jeduzizonox/current_affairs_in_english_2018_with_answers.pdf
    • https://uploads.strikinglycdn.com/files/ce9dcc35-d70d-400c-8c8b-17ea7f0c955f/zumatatugafuvemogaxexo.pdf
    • https://uploads.strikinglycdn.com/files/157a9c8c-bc67-4d7c-ae65-053ed3237a03/free_download_adobe_photoshop_cs5_full_version_with_serial_key.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d02b.bin
a0bc137f4ba13bf65cbbb94ee9686c9f7a54cebf89f96c9d0bed31cd07063b50
pdf-font-stream PDF embedded font (sfnt) at offset 0xD02B 4932 bytes
font_01_sfnt_off0000e0df.bin
9aa18ca6b9e8aba45a61e367b48d5c5f6515553eee195d8a36b0e5b19111e38e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE0DF 9920 bytes
font_02_sfnt_off00010217.bin
1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361
pdf-font-stream PDF embedded font (sfnt) at offset 0x10217 4324 bytes