Malicious PDF — malware analysis report

Static analysis result for SHA-256 31a1a8a8be986deb…

MALICIOUS

PDF

93.3 KB Created: 2020-06-04 23:23:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3510c1a71bd6847004746cf3052412af SHA-1: e62aefa0770432f628e4bee495c286357b6fdb56 SHA-256: 31a1a8a8be986deb39b9695f101d2557fef67838261b569cb12bfc0f0d8d32d2
94 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a large number of external links, many of which point to similarly structured URLs on various domains, indicating a link farm or SEO abuse tactic. The ML classifier strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains a URL that appears to be a lure for a textbook test bank, likely intended to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 4

  • 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 http://mobility-partner-program.com/uploads/1/3/0/2/130287426/130287426.html#human+development+a+lifespan+view+7th+edition+test+bank
    • http://sdstategreeks.com/uploads/1/3/1/4/131438874/bd2a33ce0e54f.pdf
    • http://ldsdailyscripture.org/uploads/1/3/0/6/130604251/detaredomejoku-jiwajedurasaga-gojopididef-boduselubivumod.pdf
    • http://bethcasteel.com/uploads/1/3/0/5/130590456/nagone_fabomarip_buluzazekidabu.pdf
    • http://jfongsg.com/uploads/1/3/0/6/130639803/aaf0b853a506.pdf
    • http://cpanel.onecoopedchick.com/uploads/1/3/0/7/130740375/8ff22.pdf
    • http://harrisonyearbook.com/uploads/1/3/1/3/131380689/seladigulimepozo.pdf
    • http://austinpanthersgarcia.com/uploads/1/3/0/6/130639540/1a5ed6e.pdf
    • http://premiertravelescapes.info/uploads/1/3/1/4/131409621/7914394.pdf
    • http://sxull.net/uploads/1/3/0/3/130312991/f649f77213d446.pdf
    • http://mobility-partner-program.com/uploads/1/3/0/2/130287426/terms.html
    • http://mobility-partner-program.com/uploads/1/3/0/2/130287426/dmca.html
    • http://mobility-partner-program.com/uploads/1/3/0/2/130287426/policy.html
    • https://vovikipima.files.wordpress.com/2020/06/15889954225.pdf
    • https://badiwilam.files.wordpress.com/2020/06/govonok.pdf
    • https://zimugubenuze.files.wordpress.com/2020/06/74319657678.pdf
    • https://pejeririp285269328.files.wordpress.com/2020/06/denanekoxuvagifikoraz.pdf
    • https://nibijolor.files.wordpress.com/2020/06/borojavigo.pdf
    • https://lomifaka595990757.files.wordpress.com/2020/06/zodofa.pdf
    • https://vomoxutufago.files.wordpress.com/2020/06/sexezixojinigopimodopa.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_off00012a18.bin
df40920f4fda2eaa58beac79e7165a54503234f1d3de20bd22bcfa694d5140c1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A18 11892 bytes
font_01_sfnt_off00015127.bin
c988415812f594187b0a0ed75dc52802e798e1695b49bd300f8412a65040a449
pdf-font-stream PDF embedded font (sfnt) at offset 0x15127 16204 bytes