Malicious PDF — malware analysis report

Static analysis result for SHA-256 55c6af157e201f34…

MALICIOUS

PDF

41.7 KB Created: 2020-08-21 02:14:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e49ba4a459c4404ff9b2143b4917e9c5 SHA-1: de064646bfadab7d5d66fc457ddc3efd2c8146ba SHA-256: 55c6af157e201f342084cb0de19d8545d21c2eaaf261d13acd66b3b4a04c3c31
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Phishing: Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a mass external link farm, with one critical link pointing to a known malicious redirector. The document body, though heavily obfuscated, contains the URL that is also present in the heuristics. This suggests the primary goal is to redirect the user to malicious infrastructure, likely for further exploitation or phishing. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://ttraff.ru/pify?keyword=yeastar+s100+voip+pbx+datasheet
    • http://ninit.nebraskafarmdog.net/uploads/1/3/1/3/131384536/6fe2bd485b6e20f.pdf
    • http://jibip.edbertcheng.com/uploads/1/3/2/8/132814930/jixabazaje.pdf
    • https://cdn.shopify.com/s/files/1/0434/5951/0424/files/fudavotuko.pdf
    • https://cdn.shopify.com/s/files/1/0430/0197/0837/files/learn_french_for_beginners_through_english.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/tovovowegafakaroseras.pdf
    • https://cdn.shopify.com/s/files/1/0434/4463/3750/files/59097287689.pdf
    • https://cdn.shopify.com/s/files/1/0433/5003/2549/files/56813244171.pdf
    • https://cdn.shopify.com/s/files/1/0430/8130/2167/files/gurigezikobajizefax.pdf
    • https://cdn.shopify.com/s/files/1/0430/0079/1191/files/windows_7_bootable_usb_drive.pdf
    • https://cdn.shopify.com/s/files/1/0430/6219/8425/files/99068438284.pdf
    • https://cdn.shopify.com/s/files/1/0433/2909/3784/files/50982894712.pdf
    • https://cdn.shopify.com/s/files/1/0437/3934/9146/files/refokozusoxozosimu.pdf
    • https://cdn.shopify.com/s/files/1/0430/5921/6533/files/acreditao_canadense.pdf
    • https://cdn.shopify.com/s/files/1/0434/4853/3144/files/introduction_to_sanitary_engineering.pdf
    • https://cdn.shopify.com/s/files/1/0437/2178/5498/files/imperative_english_exercises.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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000063f4.bin
7da402a297eb56ec1352b3c159887974e2282c6dbc51ff858f40cabf88656da0
pdf-font-stream PDF embedded font (sfnt) at offset 0x63F4 5436 bytes
font_01_sfnt_off0000766a.bin
d69b9f03ae417288c5d642d1b01f49388655ee132d610bc86a836fa81aeaf85c
pdf-font-stream PDF embedded font (sfnt) at offset 0x766A 10416 bytes